719 results about "Shaft voltage" patented technology

The invention belongs to the technical field of motor control, and relates to a permanent magnet synchronous motor sensorless control method, system and hardware circuit, angular velocity estimation is designed based on a q-axis current model under a two-phase rotating coordinate system, angular velocity estimation compensation is designed based on a d-axis current model, and a rotating speed correction coefficient is introduced. And dynamic compensation of the estimated angular velocity value is realized. An accurate angular velocity estimated value and an accurate rotor angle estimated value are obtained by constructing a Romberg observer with an angular velocity estimated value and a rotor angle estimated value as outputs based on a dq rotating coordinate system. Taking an angular velocity error obtained by a motor angular velocity given value and a motor angular velocity estimated value as input of an outer ring PI controller, so as to ensure that the angular velocity estimated value tracks the motor angular velocity given value and output a q-axis current reference value; taking the difference value between the q-axis current reference value and the q-axis current sampling value and the difference value between the d-axis current reference value and the d-axis current sampling value as the input of an inner ring PI controller so as to ensure the bandwidth and the influence capability on the load, and outputting a d-axis voltage reference value and a q-axis voltage reference value; and converting the d-axis voltage reference value and the q-axis voltage reference value into voltage reference values under a two-phase static coordinate system based on the rotor angle estimation value so as to divide SVPWM drive circuit sectors, select voltage vectors, calculate action time, control on and off time of a permanent magnet synchronous motor switching device, and control on-off time of the permanent magnet synchronous motor switching device. And the alternating current speed regulation performance of the permanent magnet synchronous motor without the position sensor under the Romberg observer method is ensured.

The invention relates to a PINN-based permanent magnet synchronous motor parameter identification method. The invention relates to the technical field of permanent magnet synchronous motor driving control, and the method comprises the steps: collecting motor operation parameters, and obtaining the quadrature-direct axis voltage, current and electrical angular velocity of a motor; a PMSM model is built; a PINN model is built; and performing finite element simulation according to the established model to obtain motor operation data, and identifying motor parameters. Compared with a traditional permanent magnet synchronous motor model, the method is higher in precision, and solves the problems that the control performance of the motor is reduced, the dynamic response is not accurate and the efficiency is low due to the influence of a traditional motor equation under a high-load or complex working condition, so as to guarantee the efficient and stable operation of the motor.

The invention relates to the technical field of electric corrosion prevention of motors, and discloses an electric corrosion prevention mechanism of a motor bearing, which comprises a motor, the motor is provided with a shell and a bottom cover which are matched with each other, a first bearing cover is fixed on the outer side of the shell, and a second bearing cover is integrally formed on the outer side of the bottom cover. Matched bearings are limited in the first bearing cover and the second bearing cover; a conduction mechanism is arranged between the shell and the bottom cover and is used for reducing the risk that the bearing matched with the bearing is electrically corroded; the outer sides of the two matching bearings are provided with conduction matching parts, and the conduction matching parts are internally provided with lubricating oil. Lubricating oil at the lower end of the rectangular block enters the annular groove to be in contact with the matched bearing through rotation of the rotating shaft, current is prevented from passing through a bearing raceway, and shaft voltage is prevented from puncturing a lubricating film to cause discharge; the motor vibrates to replace the lubricating oil in the annular groove, so that a continuously updated lubricating film is formed on the surface of the rotating element, and the insulation performance is prevented from being reduced.

The invention discloses a control method, device and equipment for a current loop of a permanent magnet synchronous motor and a storage medium, and relates to the technical field of electric vehicle driving motors, and the control method for the current loop of the permanent magnet synchronous motor comprises the steps: obtaining an input voltage; a current loop is controlled according to a target motor mathematical model and the input voltage, the target motor mathematical model is obtained by adjusting an initial model, and adjustment is based on the required torque, a rectangular axis open-loop transfer function and a zero-pole mutual elimination function. The initial model is constructed according to a target quadrature-axis voltage equation, a dynamic inductance parameter value, a locked-rotor test and a difference strategy, and the dynamic inductance parameter value and the target quadrature-axis voltage equation are at least calculated by three items of an initial quadrature-axis voltage equation, dynamic inductance, a quadrature-axis flux linkage equation and a back electromotive force-flux linkage relation. According to the invention, the control precision, efficiency and response speed of the permanent magnet synchronous motor are improved, and the robustness of the system is enhanced.

The invention belongs to the technical field of AC motor transmission control, and relates to a permanent magnet synchronous motor dead zone compensation method based on a nonlinear flux observer. Measuring a motor induction current under a natural coordinate system, and obtaining an alpha-beta axis current through conversion; a non-linear flux observer in an alpha-beta coordinate system is used as a position observation model to obtain an actual rotor position estimation value, a rotating speed ring is formed, and sensorless control of the permanent magnet synchronous motor is achieved; constructing a q-axis voltage disturbance observer by measuring the phase voltage output by the inverter; taking the output of the q-axis disturbance observer as the input of a dead time calculation module to obtain a dead time estimation value; and according to the estimated value, calculating and obtaining a dead-zone compensation voltage, and compensating the output phase voltage of the inverter to realize dead-zone compensation. On the basis of a non-linear flux observer, a position-free control closed-loop structure is constructed, and instruction voltage is corrected, so that the influence of inverter dead time on the permanent magnet synchronous motor is reduced, and the position-free control performance is improved.

The invention relates to the technical field of servo control, in particular to a high-precision current closed-loop control system and method for a servo driver, and the method comprises the steps: collecting three-phase current, rotor position, winding temperature and bus voltage, and constructing a state data set; constructing a parameter identification model fusing physical prior and an attention mechanism, deducing inductance and flux linkage parameters influenced by temperature, saturation and cross coupling, and correcting a motor model in real time; the correction parameters are injected into an FOC decoupling and feedforward link, and a self-adaptive PI regulator is linked to set the gain of a current loop on line; calculating a d-q axis voltage command according to the update model to respectively control excitation and torque components; an extended state observer is introduced to estimate load abrupt change and parameter disturbance, feed-forward compensation is carried out, and three-phase PWM is generated through anti-Parker and SVPWM; and an inverter nonlinear compensation model of a dead zone and switch delay is constructed, PWM is pre-distorted and output to a power device, and robust and low-ripple current closed-loop control of the servo motor is realized.

The invention discloses an oscillation suppression method, an inverter controller and an oscillation suppression system, and relates to the technical field of new energy. The oscillation suppression method comprises the following steps: acquiring a first active power value and a first reactive power value of a first inverter; determining an output voltage phase angle and a target induced electromotive force amplitude of the first inverter according to the first active power value and the first reactive power value; determining a d-axis voltage reference value and a q-axis voltage reference value of the first inverter according to the output voltage phase angle and the target induced electromotive force amplitude; and according to the d-axis voltage reference value and the q-axis voltage reference value, performing voltage and current double-loop control to obtain a target pulse width modulation signal. According to the embodiment of the invention, the method can offset the negative damping of the oscillation suppression system and suppress the low-frequency oscillation of the oscillation suppression system on the premise that the network-side impedance and the control parameters of the matched rectifier are not accurately obtained.

The invention discloses an adaptive current decoupling control method for a sliding mode of a permanent magnet synchronous motor, and the method comprises the steps: designing an extended state observer to observe a d-q axis current and a voltage disturbance term, carrying out the difference between a current observation value and a reference current, and inputting the difference into a non-singular integral terminal sliding mode controller, thereby obtaining a d-q axis voltage; and then the observed d-q axis voltage disturbance term is superposed to form a total d-q axis voltage. And then identifying the d-q axis inductance and permanent magnet flux linkage of the permanent magnet synchronous motor by using a recursive least square method with dynamic forgetting and adaptive regularization factors, and sending the d-q axis inductance into the extended state observer to realize a closed-loop adaptive extended state observer. And after coordinate transformation and space vector pulse width modulation are carried out on the d-q axis total voltage, the d-q axis total voltage is used for driving an inverter to control the permanent magnet synchronous motor. The method improves the current decoupling effect and anti-disturbance capability of the permanent magnet synchronous motor, adaptively adjusts the parameters of the controller according to the change of working conditions, and improves the robustness of the system.

The invention discloses an anti-backlash control method and device for a single-inverter dual-motor parallel system based on an extended state observer. Comprising the following steps: acquiring mechanical angular speeds of two motors, direct-axis current feedback, quadrature-axis current feedback and position feedback of a first motor; obtaining an average angular velocity observation value and a disturbance observation value by using an extended state observer according to the mechanical angular velocities of the two motors and the quadrature-axis current feedback of the first motor; obtaining a rotating speed reference value according to the position feedback and a preset position reference; obtaining a quadrature-axis current reference according to the rotating speed reference value, the average angular speed observation value and the disturbance observation value; obtaining an alpha-axis voltage reference and a beta-axis voltage reference of the first motor according to the quadrature-axis current reference, the direct-axis current feedback and the quadrature-axis current feedback of the first motor and the position feedback; and controlling the three-phase input voltage of the two motors according to the alpha-axis voltage reference and the beta-axis voltage reference of the first motor. According to the method, stable speed control and accurate position tracking can be realized.

The invention belongs to the technical field of industrial control, and particularly relates to a brushless direct current motor high-efficiency control method and system based on an FOC algorithm, and the method comprises the steps: superposing high-frequency sine disturbance in a voltage instruction, extracting a response component, achieving the online identification of the equivalent impedance of a motor, and dynamically solving and updating the estimated values of resistance and inductance; and correcting d-axis and q-axis voltage feed-forward items in real time by using the updated parameters, and correspondingly adjusting a current loop proportion and an integral gain. The method can adapt to the time-varying characteristics of motor parameters in an industrial field, so that the accuracy of feed-forward compensation and the stability of current loop bandwidth are effectively guaranteed, and the robustness and the control precision of a control system under complicated industrial working conditions such as variable temperature and variable load are remarkably improved; and the requirements of high-end industrial equipment on high performance and high reliability of the motor driving system are met.

The invention discloses a motor shaft voltage testing device, solves the problem of testing difficulty caused by the existence of a coupler at a motor transmission end, is simple and adjustable in structure, can be suitable for a narrow space, and belongs to the technical field of shaft voltage testing devices. The device comprises a data acquisition instrument and an electric brush assembly, a voltage sensor in the data acquisition instrument is connected with the electric brush assembly and a reference ground through electric wires, the electric brush assembly comprises an electric brush box and an electric brush part, the electric brush part is connected with a spring in an insulated mode, and the spring is installed in the electric brush box. The electric brush part slides in the electric brush box through a spring, the electric brush part is connected with an electric wire, and the bottom of the electric brush box is provided with a threading hole for the electric wire to pass through.

The invention discloses a permanent magnet synchronous motor extremely-low-speed robust position sensorless control method, device and system. The method comprises the following steps: performing ESO current-disturbance observation on dq-axis current values, voltage reference values and rotor position information at a k moment to obtain an observation current and a q-axis disturbance observation value at a k + 1 moment; the dq-axis current value, the observation current and the dq-axis current reference value at the k moment are observed through a rotor position observer, and the position and the rotating speed of a motor rotor at the k + 1 moment are obtained; adopting a feed-forward compensation method to obtain a q-axis voltage feed-forward value at the k + 1 moment according to the q-axis disturbance observation value at the k + 1 moment and the rotating speed of the motor at the k + 1 moment; and dynamically adjusting a q-axis voltage feed-forward value according to the position of the motor rotor at the k + 1 moment and the q-axis disturbance observation value, and realizing effective suppression of the torque ripple in the low-speed region. According to the method, the robustness and the anti-interference capability of a low-speed region are enhanced while the steady-state performance and the dynamic response of the system are improved.

A system for measuring generator shaft voltage and shaft current, which system relates to the technical field of power systems. The system comprises a mounting component (100), which is used for mounting grounding carbon brushes (200) on a rotating shaft of a generator at the end that is close to an exciter and at the end that is close to a steam turbine, wherein the grounding carbon brushes (200) include a first grounding carbon brush (201) and a second grounding carbon brush (202) which are located at the steam turbine end of the generator, and a third grounding carbon brush (203) at the exciter end thereof; and by means of monitoring shaft voltage and shaft current in real time, a processing module (303) calculates key parameters and performs real-time analysis and spectrum analysis. When a monitored value exceeds a threshold value, the system immediately issues an alarm, thereby effectively realizing the real-time determination of the operating state of a generator and fault early warning. Moreover, the system has the functions of storing and querying historical data, by means of which operators can evaluate the insulation performance of a generator shaft and predict potential problems, and thus prevent insulation accidents caused by an overly high shaft current, thereby prolonging the service life of devices, and ensuring the continuity and stability of a power production process.

The invention relates to the technical field of motor control, in particular to a control method and system for a motor. The method comprises the following steps that a motor main control unit MCU obtains a motor angle parameter by obtaining a corresponding target motor rotating speed set by a receiving user and carrying out angle parameter reverse solution endowing; obtaining a direct axis direction current and a cross axis direction current and carrying out motor load control calculation to obtain a direct axis voltage control quantity and a cross axis voltage control quantity; transmitting the motor angle parameter, the direct axis voltage control quantity and the cross axis voltage control quantity to a space vector pulse width modulation (SVPWM) module and carrying out SVPWM modulation processing to generate a motor rotor control SVPWM waveform; and determining a phase voltage control value applied to each motor winding, carrying out control duty ratio adjustment analysis, and controlling the corresponding rotating speed and direction of each motor at the same time. The operation efficiency and the response speed of the motor can be improved.

The utility model discloses a generator and a cleaning device for a rotor shaft of the generator. The cleaning device comprises a permanent magnet, a cleaning brush, an electric signal acquisition device, a control device and an electromagnet, the permanent magnet is fixedly connected with the cleaning brush; the cleaning brush is arranged on the outer side of the generator rotor shaft; the electric signal acquisition device is used for acquiring electric signals of a generator rotor shaft; the control device is connected with the electric signal acquisition device and the electromagnet; the control device is configured to control the power-on state of the electromagnet according to the electric signal; the power-on state comprises a power-on state and a non-power-on state; the power-on state comprises a reverse power-on state; and when the electromagnet is in a non-electrified state or a reverse electrified state, the permanent magnet is far away from the electromagnet and drives the cleaning brush to move towards one side of the generator rotor shaft, so that the cleaning brush is in contact with the generator rotor shaft. According to the technical scheme, the generator rotor shaft can be automatically cleaned, the processing efficiency of generator shaft voltage high alarm is improved, and the operation and maintenance cost of power generation is reduced.

The invention discloses a VSG transient stability control method based on PSS power angle compensation and integral reactive loop cooperation, and the method comprises the steps: constructing an improved rotor motion equation compensation mechanism based on a power system stabilizer, and based on the dynamic parameters of the voltages vabc and pcc at a PCC point and the currents iabc and pcc flowing into the PCC point which are collected in real time, carrying out the compensation of the current iabc and pcc at the PCC point under the condition that the working condition is that the voltage of a power grid drops greatly. The dynamic characteristic of active power is ensured; constructing a PSS parameter optimization method based on zero point position constraint; an integral link is embedded in the traditional voltage-reactive droop characteristic, integral reactive loop control is constructed, and steady-state voltage deviation is eliminated; the output compensation power angle delta and the output voltage amplitude E are cooperatively applied and converted into dq-axis voltage components Ed and Eq, the dq-axis voltage components Ed and Eq are sent to a voltage and current double closed loop, a driving signal is generated through SVPWM, and the stability of the system is enhanced.

The invention provides a network construction control method and system for a static var generator without a super capacitor, and the method comprises the steps: obtaining a variable needed by the control of the static var generator, comprise a three-phase bridge arm voltage measurement value, a three-phase bridge arm voltage instruction value, a reactive power instruction value, an alternating voltage amplitude instruction value, an output reactive power measurement value, an output alternating current measurement value, an alternating voltage amplitude measurement value of a common coupling point, a direct-axis voltage measurement value and a quadrature-axis voltage measurement value; obtaining a three-phase modulation voltage through a voltage loop and an alternating current loop according to variables required by control and based on direct current voltage-frequency-phase control and reactive power-voltage droop control; and obtaining a switch tube control signal according to the three-phase modulation voltage, and completing network construction control of the static var generator according to the switch tube control signal. According to the invention, the stability of the DC voltage of the static var generator can be ensured without adding a super capacitor, and active support is provided for an AC side power grid.

The invention discloses a complex wave-based permanent magnet synchronous motor all-electrical parameter online identification method and device. The method comprises the following steps: analyzing the influence of a voltage error caused by dead zone time on parameter identification, and performing corresponding dead zone compensation; a bias complex wave with a certain amplitude and frequency is injected into the d-axis current, so that the d-axis current meets a parameter identification continuous excitation condition; constructing three groups of effective current slopes through four groups of different input data stored in the steady state of the motor, and identifying three groups of parameters of resistance, direct-axis inductance and quadrature-axis inductance by referring to a d-axis voltage equation and adopting a least square method with a forgetting factor; and finally, updating the identified three groups of parameters as known quantities in a q-axis voltage equation in real time, storing two groups of different input data to construct a group of effective current slopes, and identifying flux linkage parameters by adopting a least square method with a forgetting factor. According to the method, the under-rank problem of all-electrical parameter identification of the motor is solved, the identification precision is high, and the identification error of each parameter is about 3%.

The invention discloses a two-degree-of-freedom permanent magnet synchronous motor driving method and a driving device thereof. A current instruction value of a d-q axis passes through a first coordinate conversion module to obtain an instruction value of a three-phase stator current; then comparing with a three-phase current actual value fed back by sampling, and obtaining a feedback item of a three-phase instruction voltage through a PI regulator module; deriving a recursive relational expression of d-q axis current along with the change of the control period, processing three-phase voltage fed back by the motor through a third coordinate transformation module to obtain d-q axis voltage, substituting the feedback three-phase current through a second coordinate transformation module to obtain d-q axis current and a d-q axis current instruction value into the recursive relational expression, and finally obtaining a three-phase instruction voltage feed-forward item; and adding the feed-forward item and the feedback item to obtain a three-phase voltage instruction value, inputting the three-phase voltage instruction value into a switch function module, determining a power device in the controlled three-level inverter bridge module according to the positive and negative of each instruction value, comparing the power device with a carrier wave to obtain a required PWM wave, and finally obtaining an alternating current and outputting the alternating current to the three-phase permanent magnet synchronous motor.

The invention discloses a method and a device for zero calibration of a motor, a storage medium and the motor. The method comprises the following steps: determining an initial zero angle of the motor; inputting current to the motor under the current carrier frequency to drive the motor to rotate forwards; after the rotating speed of the motor reaches the target rotating speed, the speed of the motor is freely reduced, and the PI controller determines a first zero angle enabling the d-axis voltage of the motor to be zero by taking the initial zero angle as a reference; and then the motor is driven to rotate reversely, and a second zero angle enabling the d-axis voltage of the motor to be zero is determined. And determining a third zero angle corresponding to the current carrier frequency according to the first zero angle and the second zero angle. And under different carrier frequencies, the PI controller respectively and repeatedly executes calibration operation by taking the third zero angle as a reference so as to obtain each target zero angle corresponding to each different carrier frequency. According to the scheme, the zero angles under different carrier frequencies are calibrated based on the calibrated zero angle, the calibration result is more accurate, and the efficiency is higher.

The invention provides a hydro-generator shaft insulation multi-parameter monitoring method and system, and the method comprises the steps: employing a common excitation proportion method, introducing a high-frequency excitation current source through a grounding brush, loading a high-frequency voltage on the basis of a shaft voltage, respectively detecting an oil film voltage and an insulation pad voltage, and calculating a voltage amplitude ratio, analyzing oil film capacitance and insulation capacitance based on the high-frequency signal; a co-excitation polling method is adopted, high-frequency excitation current paths are sequentially switched through a polling device, high-frequency current flows through different impedance branches, high-frequency and low-frequency voltage signals are separated through a frequency-selecting filter, and oil film impedance and insulation impedance are analyzed; an independent excitation method is adopted, a high-frequency excitation source is independently introduced from a bearing bush, a frequency-selecting filter or an impedance converter is combined, independent measurement of oil film impedance and insulation impedance is achieved, and oil film thickness and insulation parameters are calculated. According to the invention, multi-parameter monitoring of bearing insulation can be realized.

The invention discloses a bearing electrocorrosion prediction method, device and equipment and a storage medium, and relates to the technical field of electromechanical system design, and the bearing electrocorrosion prediction method comprises the steps: obtaining motor information and bearing information; obtaining a shaft voltage based on motor information and the bearing information; determining a shaft current density based on the bearing information and the shaft voltage; and completing bearing electrocorrosion prediction based on the shaft voltage and the shaft current density. The shaft voltage and the shaft current density generated in the operation process of the motor are calculated through the analytical method, the risk of electrocorrosion of the bearing can be predicted, design parameters of the motor and the bearing can be optimized, it is ensured that the motor cannot be damaged due to electrocorrosion in the operation process, the reliability of the motor is improved, and the service life of the motor is prolonged. The electric corrosion risk can be evaluated in the design stage, the test frequency is reduced, the development period is shortened, the development cost is reduced, it is ensured that the motor is still safe and reliable under the operation conditions of high voltage, high integration and the like, and wide application prospects are achieved.

In a general aspect, a method includes measuring, for a permanent magnet motor having a rotor rotating at a speed, a direct-axis voltage in a rotor frame of reference. The speed is determined by an angular position sensor. The method further includes comparing the measured direct-axis voltage with a reference voltage, and determining, based on the comparing, an angle offset estimate of the angular position sensor. The method also includes iteratively adjusting the angle offset estimate until the measured direct-axis voltage substantially equals the reference voltage.

The invention discloses a non-electrolytic capacitor permanent magnet synchronous motor torque ripple suppression method and device based on current harmonic injection, and belongs to the field of permanent magnet synchronous motor control, and the method comprises the steps: enabling the power of an inverter to be equal to the ideal network side input power as a target, carrying out the harmonic injection of a q-axis current given reference value Iq0, and obtaining a reference value Iq0; and performing harmonic injection on a d-axis current given reference value Id0 to obtain a d-axis current reference value # imgabs1 #, performing PI control on differences between the d-axis current reference value and the q-axis feedback current and between the d-axis current reference value and the q-axis current reference value and between the d-axis current reference value and the q-axis feedback current after PI control is performed on the d-axis current reference value and the q-axis current reference value, adding the d-axis current reference value and the q-axis current reference value to d-axis feed-forward structure voltage and q-axis feed-forward structure voltage of the motor to obtain a d-axis current reference value # imgabs0 # and a q-axis current reference value # imgabs1 #. And 4, obtaining d and q axis voltage reference values # imgabs2 #, converting # imgabs3 # into alpha and beta axis voltage reference values, and generating PWM (Pulse Width Modulation) signals for controlling each switching tube in the inverter. According to the invention, on the premise of not increasing extra hardware cost, the torque ripple of the output torque is effectively reduced, and meanwhile, a high input power factor is realized.

The invention relates to an optimal power capturing method for a wave energy power generation device of a mixed-flow type air turbine, and belongs to the field of wave energy power generation. The optimal power capturing method comprises the steps that the change condition of the average output power of the turbine under different sea conditions along with the rotating speed is tested, and the maximum average output power point of the turbine under each sea condition is obtained; fitting the maximum average output power point under each sea condition to obtain a control law of the electromagnetic power of the motor; the quadrature-axis current reference value of the stator is made to be equal to zero, and the direct-axis current reference value of the stator is calculated; calculating a stator quadrature-direct axis current error term, and establishing a positive definite Lyapunov function; deriving the Lyapunov function, substituting the Lyapunov function into a stator quadrature-direct axis current state equation, and then performing transformation according to a first stability theorem to obtain a stator quadrature-direct axis voltage control law; and generating a corresponding SVPWM (Space Vector Pulse Width Modulation) switching signal according to a stator quadrature-axis voltage control law so as to control a motor-side converter and realize control on a turbine. The wave energy capturing efficiency can be improved.

The invention discloses a permanent magnet synchronous motor temperature monitoring and demagnetization early warning method based on chaotic signal injection and multi-parameter fusion. Comprising the steps of 1, generating a wide-spectrum chaotic signal based on a Lorenz chaotic system, and injecting the wide-spectrum chaotic signal into a d-axis voltage channel of a d-q-axis mathematical model of the permanent magnet synchronous motor; 2, identifying stator resistance RS and d-axis inductance Ld by using a least square method; 3, a Kalman state space model with the winding temperature Tw and the magnetic steel temperature Tm as state variables is constructed, the resistance Rs and the inductance Ld which are measured in real time are fused, the observation noise covariance R is adjusted in a self-adaptive mode, and the winding temperature Tw and the magnetic steel temperature Tm are output in a decoupling mode; step 4, establishing a motor back electromotive force model to calculate a real-time flux linkage psi f, and calculating a motor temperature rise rate # imgabs0 # through a sliding window weighted average method; and step 5, performing demagnetization risk grading early warning according to the flux linkage and the temperature rise rate of the motor.

The invention relates to a bearing electrocorrosion detection method, system, device and equipment and a medium. The bearing electrocorrosion detection method is applied to detection equipment, one end of the detection equipment is in contact with a test point, close to a bearing inner ring, on a rotating shaft through a rotating shaft signal lead of a test probe, and the other end of the detection equipment is in contact with a test point, close to a bearing outer ring, on a motor shell through a shell signal lead. The detection equipment detects the shaft voltage waveform of the bearing when the motor is in the target working condition, judges whether the bearing has an electro-corrosion risk under the target working condition according to the shaft voltage waveform, and if yes, after the insulating bearing is replaced, the rotating shaft signal lead and the shell signal lead are in short circuit, and the shaft current under the target working condition is detected; and evaluating the electric corrosion severity of the bearing under the target working condition according to the shaft current. By implementing the bearing electrocorrosion detection method provided by the invention, the problem of inaccurate bearing electrocorrosion detection in the prior art can be improved.

The invention relates to a permanent magnet synchronous motor current loop control method which is executed by a vehicle and comprises the following steps: acquiring real-time current passing through a permanent magnet synchronous motor stator winding of the vehicle under a three-phase static coordinate system; converting the real-time current under the three-phase static coordinate system into a d-axis current and a q-axis current under a two-phase rotating coordinate system; generating a d-axis voltage signal and a q-axis voltage signal according to the d-axis current, the q-axis current, the rotating speed of the motor and the current command; performing decoupling operation on the d-axis voltage signal and the q-axis voltage signal to obtain a d-axis command voltage and a q-axis command voltage; obtaining an overcurrent fault flag bit according to the d-axis current and the q-axis current; determining PWM switching frequency and current loop PI controller parameters based on the rotating speed of the motor; and controlling a permanent magnet synchronous motor current loop in the vehicle according to the d-axis voltage signal, the q-axis voltage signal, the overcurrent fault flag bit, the PWM switching frequency and the parameters of the current loop PI controller.

The invention discloses a self-adaptive field weakening control method for a permanent magnet synchronous motor, and the method comprises the following steps: 1, obtaining a difference value between a reference rotating speed and an actual rotating speed, and carrying out the PI operation of the difference value to obtain a reference current vector amplitude; 2, obtaining a difference value between the maximum reference torque angle and the current torque angle, carrying out PI operation on the difference value, and multiplying a PI operation result by the adaptive gain to obtain a compensation value of a reference current vector amplitude; 3, compensating the reference current vector amplitude through the compensation value to obtain an optimal reference current vector amplitude; obtaining a reference quadrature-axis current and a reference direct-axis current through the optimal reference current vector amplitude; 4, obtaining a reference quadrature-axis voltage and a reference direct-axis voltage, and carrying out amplitude limiting on the reference quadrature-axis voltage and the reference direct-axis voltage; and step 5, performing field weakening control on the permanent magnet synchronous motor according to the reference quadrature-axis voltage and the reference direct-axis voltage after amplitude limiting. According to the invention, low-development and high-reliability field weakening control can be realized.

The invention discloses a hybrid excitation synchronous motor control method and system, and belongs to the technical field of motor control. The problem that a motor control system can operate at high precision when a position sensor breaks down is mainly solved. The method comprises the following steps that when a position sensor breaks down, a system is switched to an active short circuit protection (ASC) mode, and operation of a motor is controlled by giving instruction values of d-axis current and q-axis current in the mode; then, in an ASC mode, estimating a rotor angle through a voltage equation in a static coordinate system, so as to obtain an electrical angle of a rotor; after the rotor angle estimation is completed, the system is switched from the ASC mode to the vector control mode without the position sensor, and the d-axis voltage and the q-axis voltage are adjusted in the mode, so that the motor can be continuously and accurately controlled and stably run. The invention provides an efficient and safe motor control method, and the safety and reliability of the electric vehicle under the condition of sensor fault are effectively improved.