419 results about "Vector control" patented technology

The invention discloses a motor control method and device, electronic equipment and a storage medium. The method comprises the following steps: acquiring a three-phase current, converting the three-phase current into a total current of a current period in a static coordinate system, and extracting a high-frequency current of the current period from the total current; extracting a rotor position and a rotor rotating speed from the high-frequency current; compensating the rotor rotating speed by using the expected rotating speed to obtain a quadrature-axis expected current; converting the total current into a quadrature-direct axis coordinate system, extracting a fundamental frequency current from the quadrature-direct axis coordinate system, compensating the fundamental frequency current by using a quadrature axis expected current and a direct axis bias current to obtain a first expected voltage, superposing the first expected voltage and a direct axis high-frequency voltage, and performing coordinate system conversion on a superposition result by using a rotor position to obtain a second expected voltage; obtaining a second expected voltage under the static coordinate system; and the three-phase current of the current period is controlled according to the second expected voltage to drive the motor, so that the motor has more obvious salient polarity through the direct-axis bias current, and vector control over the electrode is achieved.

The invention discloses an EHA drive control system three-closed-loop control system and a dynamic hysteresis compensation method. The technical problems that an existing electro-hydrostatic actuator is large in hydraulic hysteresis error, poor in dynamic response and insufficient in environmental adaptability are solved. The method comprises a three-stage control structure of a position control loop, a speed control loop and a current control loop, the position control loop introduces load disturbance feed-forward compensation based on a state observer, the speed control loop adopts an adaptive sliding mode control strategy, the current control loop executes a decoupling vector control algorithm, and the load disturbance feed-forward compensation is realized. And a dynamic hysteresis compensation model based on historical input and disturbance estimation is established in the controller. According to the system, the servo motor, the gear pump, the hydraulic cylinder and the sensor module are integrated into an integrated drive control structure, and the effects of improving the control precision, reducing the response time delay and correcting the hydraulic hysteresis error are achieved.

The invention discloses a frequency conversion vector control method for a digital energy-saving pump station, which belongs to the technical field of vector control and comprises the following steps: constructing a coupling vector model, simulating the running states of a pump unit under different working conditions through a virtual test signal, and automatically correcting the coupling vector model; operating data of a pump set are collected in real time, an operating situation feature set is constructed, predictive vector control is carried out, an optimal voltage vector sequence is generated, and meanwhile load fluctuation of a pipe network is predicted; demand pre-judgment is carried out on the starting and stopping time and the action amplitude of the anti-backflow device, a bidirectional disturbance suppression mechanism is constructed, current vector parameters are pre-adjusted, and calculus correction is carried out based on deviation judgment; when multiple pumps operate in parallel, the instantaneous operation efficiency point of the pump set is calculated in real time, the efficiency change trend is predicted, a load distribution scheme is generated, the comprehensive energy efficiency is evaluated, energy efficiency self-optimization is carried out, the comprehensive energy efficiency of the system is improved, and control experience reuse is achieved.

The invention discloses a wireless cooperative control system and method for a multi-node brushless motor, and the system employs a layered architecture design, and comprises a main control layer, a drive layer, a communication layer, and a software layer. The master control layer is composed of a master node and serves as a task instruction scheduling center of the system, the driving layer is composed of N slave nodes, and N is larger than or equal to 3; the driving layer drives the brushless motor by executing an FOC vector control algorithm and monitors the state of the brushless motor; the communication layer constructs a star network topology based on an ESP-NOW protocol, a direct communication link is established between a master node and N slave nodes, and multi-node cooperative control is realized by adopting a dynamic channel switching mechanism and a timestamp alignment mechanism; and the software layer establishes communication with the main control layer through a USART serial port, receives the state data of the brushless motor of each slave node concentrated by the main control layer, and sends an instruction to the main control layer at the same time. Not only are wireless multi-node synchronization and anti-interference problems solved, but also high-precision motor control is realized.

The invention belongs to the technical field of power system operation and motors, and particularly relates to an energy storage type phase modifier control method which comprises the steps that a rotating shaft of a double-fed motor is connected with a flywheel to serve as an energy storage type phase modifier; the rotor winding is connected to a power grid through an excitation system and a transformer in sequence, and the excitation system is electrically connected by a reactor, a back-to-back converter and a filter in sequence; the stator winding is directly connected to a power grid; the control system decouples reactive power and active power, vector control is carried out on exciting current to absorb or release power, and reactive power-voltage support and active power-frequency support of the power grid are completed. The method overcomes the defects that a traditional direct-current excitation phase modulation mode can only modulate phase and cannot modulate frequency, or is cumbersome and slow in response. The system can meet the requirement of wide-range variable-speed operation, quickly store / release a large amount of rotor kinetic energy, inhibit the voltage and frequency fluctuation of a power grid, and is especially suitable for stations with high new energy occupation ratio. The invention also provides a non-transitory readable recording medium storing the program of the method and a system comprising the medium, and the program can be called through a processing circuit to execute the method.

The invention discloses a low-harmonic high-voltage speed regulation system based on a multi-pulse phase-shifting transformer, and particularly relates to the field of power electronic technology and motor speed regulation, which is characterized in that the primary side of the multi-pulse phase-shifting transformer is in star connection, and N groups of windings on the secondary side are in extended delta connection, so that phase difference is realized; the multi-path low-voltage alternating current is converted into multi-path low-voltage alternating current and low-order harmonics are High voltage is output through cascade H-bridge topology series connection, and reliable conversion is guaranteed through rectification filtering inversion and device redundancy design; the motor control module collects signals through multiple sensors, and PWM drive signals are generated through a vector control algorithm and coordinate transformation. The harmonic detection and compensation module detects harmonic waves based on an FFT algorithm, and injects a reverse compensation component through a modulation strategy to offset the harmonic waves; and the auxiliary protection module integrally realizes low-harmonic and high-precision high-voltage motor speed regulation through multi-dimensional monitoring and hardware protection.

The invention provides a zero-voltage ride-through control method for a self-synchronizing voltage source doubly-fed wind turbine generator, which comprises the following steps that: when the self-synchronizing voltage source doubly-fed wind turbine generator is in a transient state, a grid-side converter adopts vector control, and a rotor-side converter adopts additional virtual impedance and annular current limiting; the transient overcurrent of the grid-side converter and the rotor-side converter can be effectively suppressed, so that the continuous operation capability of the wind turbine generator in the zero-voltage ride-through period can be maintained; meanwhile, by improving the transient capacity and the transient reactive current amplitude of the converter, the transient voltage supporting capacity of the wind turbine generator during the zero voltage ride-through period can be effectively provided; when the self-synchronizing voltage source doubly-fed wind turbine generator set is in a transient state, overvoltage of direct-current bus voltage is limited by a Chopper circuit, active-priority current amplitude limiting control is adopted by a grid-side converter, parameters of a current inner ring PI controller of a rotor-side converter are optimized, energy balance of a direct-current side can be achieved in the zero-voltage ride-through period, and stability of the direct-current bus voltage is maintained.

The invention discloses a permanent magnet synchronous motor non-inductive vector control method based on SOGI-QNPLL. The method comprises the following steps: constructing a current state equation of a permanent magnet synchronous motor under a two-phase static coordinate system; constructing a new switching function, and designing and improving a full-order sliding mode observer according to the new switching function and the current state equation; the convergence of the improved full-order sliding mode observer is analyzed, and the value ranges of the gain m and the gain n of the improved full-order sliding mode observer are calculated; analyzing the improved full-order sliding-mode observer, and discretizing the improved full-order sliding-mode observer by adopting a forward Euler method; establishing a phase-locked loop (PLL), performing normalization design on the phase-locked loop, and establishing a normalized phase-locked loop (QNPLL); a second-order generalized integrator (SOGI) is established and discretized by adopting a bilinear transformation method, the discrete SOGI is combined with the QNPLL to form SOGI-QNPLL, and the SOGI-QNPLL is utilized to estimate the rotor position. According to the SOGI-QNPLL provided by the invention, the rotor position can be accurately extracted, the observation precision is remarkably improved, and the reliability and performance of the system are enhanced.

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.

The invention provides a permanent magnet synchronous motor frequency conversion soft start and grid connection device and a control method. The device comprises a power supply grid (1), a permanent magnet synchronous motor (2), three-phase contactors (3), (4) and (5), a variable frequency controller composed of a rectifier (6), an inverter (7) and a control panel (8), a voltage sampling module (9), a current sampling module (10) and a filter inductor (11) at the output end of the inverter. One end of the three-phase contactor (3) is connected with a three-phase inlet wire of the power supply grid (1), and the other end of the three-phase contactor (3) is connected with the input end of the rectifier (6); one end of the three-phase contactor (4) is connected with the output end of the inverter (7), and the other end of the three-phase contactor (4) is connected with the input end of the motor (2); and one end of the three-phase contactor (5) is connected with a three-phase inlet wire of the power supply grid (1). VF open-loop pre-synchronization control is introduced in advance in vector control, power grid synchronization conditions are simulated, a motor is enabled to actively match power grid magnetic field parameters before grid connection, smooth transition of a control mode is realized, and large impact current and electromechanical oscillation are avoided.

The invention discloses a hub motor vector control method based on an improved grey wolf particle swarm algorithm, and the method comprises the steps: building a mathematical model of a hub permanent magnet synchronous motor, building a double-closed-loop vector control simulation model containing a speed loop and a current loop in Simulink based on the mathematical model, and selecting a speed loop PID controller as a to-be-set object; improving the original grey wolf particle swarm algorithm to obtain an improved grey wolf particle swarm hybrid algorithm; and performing iterative optimization on the three parameters Kp, Ki and Kd of the speed loop PID controller through the improved grey wolf particle swarm hybrid algorithm, and outputting the finally obtained global optimal solution q as the optimal values of the three parameters Kp, Ki and Kd of the speed loop PID controller to complete the hub permanent magnet synchronous motor vector control.

The invention relates to an AC motor synchronous modulation method based on a phase-locked loop and a PWM generator, and belongs to the technical field of motor control, and the method comprises the steps: determining a voltage phase angle outputted by an AC motor based on an output voltage of vector control of the AC motor, and converting the voltage phase angle into a synchronous phase angle of a carrier wave based on a carrier wave ratio; the synchronous phase angle is used for determining a sine input signal of the phase-locked loop; determining a cycle count increment adjustment value of the carrier based on the sinusoidal input signal; and correcting the cycle count increment value of the carrier based on the cycle count increment adjustment value. According to the alternating current motor synchronous modulation method based on the phase-locked loop, the period ratio and the phase relation of the carrier wave and the modulation wave are fixed, so that the harmonic content of the output voltage and the harmonic content of the output current are kept consistent in the synchronous modulation process, extra harmonic voltage and current cannot be generated, and overall harmonic treatment of a system is facilitated.

The invention relates to the technical field of motor control, and discloses a vector control application of a direct drive motor, which comprises the following steps: S1, collecting stator current, rotor speed and bus voltage signals of the motor, and carrying out filtering preprocessing on the collected signals; and S2, constructing a self-adaptive flux linkage observation model, estimating a stator flux linkage in real time based on stator current and bus voltage signals in combination with rotor rotating speed information, and correcting stator resistance and inductance parameters through a model reference self-adaptive algorithm. According to the method, the motor parameters are corrected in real time through the self-adaptive flux linkage observation model, parameter drift caused by factors such as temperature change and magnetic saturation is effectively counteracted, and the accuracy of flux linkage estimation is improved; the improved PI regulator realizes online self-tuning of control parameters through a fuzzy control algorithm, can quickly adapt to changes of dynamic characteristics of the motor, and shortens the regulation response time of flux linkage and torque; and the resistance of the system to external interferences such as load fluctuation, power supply voltage change and the like is enhanced.

The invention discloses a high and low temperature automatic test method and system for a transmit-receive vector control module, and a medium, and belongs to the technical field of chip test. The method comprises the steps that an upper computer selects a test channel and test items and configures test parameters; the upper computer is connected with the instrument according to the test items and performs different presetting according to the test types; starting an automatic test, sending a matrix switch control instruction by the upper computer, performing switch matrix channel switching and COM port switching, and then executing SIP power-up and pole writing; executing a corresponding test process according to the test type; and after the test is completed, the SIP is powered off, poles are written, test data are stored, then whether all channels of the SIP are tested or not is judged, if not, the next channel is tested, and if all the channels are tested, all the test data are exported. Through the full-automatic testing process, manual intervention is reduced, and the testing efficiency of a production line can be greatly improved. In a high and low temperature test environment, the equipment can carry out continuous multi-channel test.

The invention relates to the technical field of automatic control, and provides a control method and a control device of a hydraulic system and engineering machinery, vector control is used for directly regulating and controlling a hydraulic pump without depending on an intermediate link of the hydraulic system, the response is at a millisecond level, and when a load suddenly changes, the torque of a motor can be quickly limited, power overshoot is avoided, and the reliability of the hydraulic system is improved. The motor and battery system is protected, closed-loop control over the rotating speed is carried out, precision is higher, the torque upper limit is controlled by directly inputting the required power, the power is limited to be kept constant, the method is suitable for various complex scenes, high-speed and large-flow operation of the variable pump during light load can be achieved, the speed requirement is met, and the working efficiency is improved. And low-speed small-flow operation is achieved during heavy load, the safety requirement is met, a constant displacement pump and / or a variable displacement pump can be compatible at the same time, the problem that constant-power control cannot be achieved through the constant displacement pump is solved, and economy and environment friendliness are achieved.

The invention relates to the technical field of motor control in the intelligent power grid industry, and discloses a space vector control method for a twelve-phase permanent magnet synchronous motor flywheel energy storage system, a control circuit of the flywheel energy storage system relates to power electronic components such as various semiconductor field-effect tubes, and the space vector control method is used for high-precision control of a motor. Comprising the steps of S1, twelve-phase space vector decoupling fault-tolerant control, S2, high-order harmonic energy recovery closed loop, S3, quantum annealing parameter optimization layer, S4, flux linkage adaptive observer network construction and S5, 18-dimensional switching vector table construction. According to the scheme, through multi-reference coordinate system transformation and a redundant phase reconstruction algorithm, rapid fault-tolerant response of the twelve-phase motor during a single-phase or two-phase fault is realized, a current path is dynamically recombined during the fault, a negative-sequence current compensation ring is combined, torque ripple is effectively suppressed, and the reliability of the motor is improved under a high-speed charging and discharging working condition. The harmonic distortion rate is detected in real time through the sliding window FFT, the bandwidth of the controller is adjusted, and the problem that the dynamic response of a traditional fault-tolerant strategy is insufficient is solved.

The invention belongs to the technical field of automation control, and particularly relates to a control parameter optimization method and system for a multistage reaction kettle, and the method comprises the steps: collecting key operation data of a series multistage reaction kettle at each moment in real time, and constructing an initial temperature sequence and an initial valve opening sequence after standardization and adaptive filtering denoising; indexes such as temperature fluctuation standard deviation are calculated based on the initial temperature sequence, the temperature deviation degree is obtained through normalized weighted fusion, and parameters such as the Arrhenius law and the actually measured temperature are combined to construct a reaction nonlinear strength index; on the basis of the index coupling initial valve opening degree sequence change rate, a model vector self-adaptive correction coefficient is obtained in combination with parameters such as a smooth factor; and correcting a basic step response vector controlled by the dynamic matrix by using the coefficient, solving an optimal valve opening adjustment amount, calculating an execution value, and outputting the execution value to an execution mechanism to complete regulation and control, thereby realizing full-cycle optimization of control parameters. According to the invention, the control accuracy of the multi-stage reaction kettle is improved.

The invention relates to the technical field of flexible interconnection power distribution networks, and discloses a frequency support control system of a doubly-fed wind turbine generator connected into a flexible interconnection power distribution network and a control method of the frequency support control system. A virtual synchronous frequency support is embedded in the doubly-fed wind turbine generator, and a fuzzy controller based on frequency deviation and change rate is introduced to realize optimization of inertia and a primary frequency modulation coefficient; the system structure can actively support the connected flexible interconnection power distribution network; according to the method, the inertia response coefficient and the primary frequency modulation coefficient can be dynamically adjusted in real time according to the system operation state, and the frequency fluctuation problem caused by the distributed power supply is solved; the inertia response coefficient and the primary frequency modulation coefficient are dynamically adjusted in real time according to the operation state of the flexible interconnection power distribution network, and it is still ensured that the doubly-fed wind turbine generator has good frequency supporting performance under the condition of wind speed fluctuation.

The invention discloses a current tracking error elimination method and system for a permanent magnet synchronous motor with a small mechanical time constant, and belongs to the technical field of permanent magnet synchronous motor control, and the method comprises the following steps: obtaining a PMSM parameter, and constructing an electrical differential equation and a mechanical differential equation of the PMSM under a dq rotating coordinate system based on the PMSM parameter; converting the electrical differential equation and the mechanical differential equation into a state-space equation in an expansion state; based on the state-space equation, constructing a relative-order expansion state observer to observe the state of the system; and a current active disturbance rejection controller is established based on the state of the system, and errors are eliminated by using the current active disturbance rejection controller. According to the method, the tracking performance and the anti-interference performance of current control are improved, the current dynamic response is optimized, and the method is a basis for realizing high-quality vector control of the PMSM with the small mechanical time constant.

The invention provides an active support self-adaptive control method for a network construction type converter. The active support self-adaptive control method for the network construction type converter comprises the following steps: S01, calculating a frequency difference value and a frequency change rate value of the network construction type converter; s02, calculating an inertia coefficient according to a frequency change degree comprehensive threshold value; s03, calculating a damping coefficient according to the frequency difference threshold value; s04, realizing active support control by simulating the characteristics of a synchronous machine; and S05, performing pulse width modulation on the internal potential through vector control. According to the active support self-adaptive control method for the network construction type converter, main parameters are self-adaptively adjusted according to the external environment of the system to suppress power and frequency fluctuation, the method can be suitable for the operation occasion of a power electronic converter, and particularly, the steady state of the network construction type converter is not influenced by external disturbance; therefore, the active support control performance of the converter is improved.

The invention discloses a torque ripple suppression method for a permanent magnet synchronous motor under a limited voltage, and belongs to the technical field of power generation, power transformation or power distribution. The method comprises the following steps: acquiring torque data changing along with a rotor position under different excitation currents, and establishing a torque three-dimensional look-up table model of the torque about a shaft current and the rotor position; respectively establishing optimization targets for a low-rotating-speed working condition and a high-rotating-speed working condition, and establishing a stator current two-dimensional table look-up model under the low-rotating-speed working condition and a stator current three-dimensional table look-up model under the high-rotating-speed working condition in combination with the torque three-dimensional table look-up model; an optimized stator current algorithm model is established according to the stator current look-up table model, the stator current two-dimensional look-up table model or the stator current three-dimensional look-up table model is switched according to the criterion of direct current voltage out-of-limit, and the query value of the optimized stator current is used as a stator current reference value for vector control of the permanent magnet synchronous motor. While low-speed copper loss reduction and high-speed speed regulation range expansion are taken into consideration, overall torque harmonic suppression under a voltage limited working condition is realized.

A washing machine is provided that accurately detects a wire break in a motor that rotates a drum and reduces the time required for wire break detection. The washing machine includes: a three-phase brushless DC motor that rotates the drum and drives a pulsator via a reduction gear; an inverter circuit that drives the motor using PWM control; a current detection unit that individually detects the three-phase current of the motor; a control unit that vector controls the motor via the inverter circuit; a wire break detection unit; and an abnormality processing unit. When the wire break detection unit detects a wire break, the unit stops the motor and issues an abnormality report. The wire break detection unit performs a smoothing process on the current value detected by the current detection unit while the motor is rotating the pulsator via the reduction gear. A wire break is detected when the difference between the current value of one phase and at least one of the other two phases remains below a predetermined value for a predetermined period of time.

To provide a method for estimating an axis error between a d-q axis and a γ-δ axis in a synchronous motor.SOLUTION: In a control method for driving a synchronous motor by sensorless vector control, a magnetic axis of a permanent magnet of the synchronous motor is defined as a d-axis, a direction orthogonal to the d-axis is defined as a q-axis, a designated magnetic axis of the synchronous motor is defined as a γ-axis, and a direction orthogonal to the γ-axis is defined as a δ-axis, and when vγ iγ+vδ iδ=P / 2 ωR ΦM iδ+R (iδ^2+iγ^2) is established, it is estimated that the d-q axis and the γ-δ axis coincide with each other without an error, and when the above expression is not established, an amount of the error is estimated from a difference between the left side and the right side. vγ represents a γ-axis voltage [V], iγ represents a γ-axis current [A], vδ represents a δ-axis voltage [V], iδ represents a δ-axis current [A], P represents a motor pole number, R represents a motor one-phase resistance value [Ω], ωR represents a motor electrical angular speed [rad / s], and ΦM represents a magnet flux [wb].SELECTED DRAWING: Figure 2

The invention discloses a method and system for applying vector control to a generalized frequency conversion system. The method comprises the steps that stator flux linkage orientation parameters and torque control parameters are generated according to high-voltage power grid operation parameters collected in real time and an obtained torque instruction; the target slip rate of the motor is dynamically determined through a slip rate limiting module so as to ensure that the inverter works in a power output or absorption safety interval; according to the target slip ratio and the torque control parameter, a rotor side voltage waveform is generated through an inverter, vector control is carried out on a motor rotor, and the torque and the rotating speed of the motor are adjusted; the stability of the system is monitored in real time through the stability augmentation device, the critical stable, over-stable or under-stable state is compensated, and the control parameters or the power grid frequency are adjusted to maintain stable operation of the system. According to the method, the variable-frequency variable-torque control precision and the response speed which are equivalent to those of a traditional high-voltage frequency converter system are achieved, and an efficient, economical and reliable speed regulation solution is provided for a power plant auxiliary engine system.

The invention discloses a high-precision vector regulation and control device and method for a signal generation link, and belongs to the technical field of information. A frequency mixing feedback loop is adopted to replace a traditional ALC detection loop, the amplitude of a signal can be stabilized, the phase of the signal can also be stabilized, and impedance matching of a channel can also be regulated and controlled; a path feedback signal is converted into a digital signal for high-speed transmission, and the ADC, the signal processing module and the DDS are interconnected through a high-speed bus, so that high-speed vector regulation and control can be quickly performed, and the loop control speed is higher; according to the invention, the direct digital frequency synthesizer is in a loop, which means that the amplitude and phase drift in the DDS can also be captured by the loop for correction; according to the method, vector information of the amplitude and phase drift of the channel can be obtained at the same time, so that closed-loop dual control, namely vector control, is carried out, and the purpose of regulating and controlling the amplitude and phase of the signal at the same time is achieved.

The application discloses a motor driving control system, an electric driving joint and a control method thereof. The control system comprises a first control module and a second control unit. The first control module comprises a first control unit, a signal gating control unit and a motor unit connected in sequence. The first control unit is configured to generate a first control signal according to the operation feedback signal of the motor unit through a vector control algorithm. The second control unit is electrically connected with the signal gating control unit. The second control unit is configured to generate a second control signal according to the operation feedback signal of the motor unit through a reinforcement learning algorithm. The signal gating control unit is configured to select the first control signal or the second control signal as a target control signal to control the operation of the motor unit according to the operation feedback signal of the motor unit and the second control signal. The application can solve the problem that the electric driving joint cannot quickly and safely and reliably adapt to different humanoid robots and has poor adaptability.

The invention provides a permanent-magnet direct-drive pressurized screen without a transmission part, and belongs to the technical field of papermaking machinery. According to the structure, a barrel is fixedly connected to the interior of a shell, a vector permanent magnet motor is fixedly connected to the interior of the barrel, a bearing is arranged in the barrel, a main shaft of the vector permanent magnet motor is connected to the bearing, a mechanical seal is arranged at the position, penetrating through the barrel, of the main shaft of the vector permanent magnet motor, and a rotor is connected to the main shaft; a screen cylinder is fixedly connected in the shell and located on the periphery of the rotor, a channel is formed in the position, located on the periphery of the main shaft and the vector permanent magnet motor, in the barrel, and a water retaining ring is arranged at the position of a lower port of the channel. The rotor of the pressure screen is directly driven in the mode that the vector-controlled permanent magnet motor stretches out of the power shaft, the disassembly, assembly and maintenance efficiency and the equipment operation safety are improved, the coaxiality of the rotor and the screen cylinder is directly guaranteed, meanwhile, certain cost is reduced, and the technical advantages are outstanding.

This invention discloses an electric tool. This electric tool solves the problem of motor overheating and burning out during prolonged operation of electric tools in related technologies. During operation, the electric tool utilizes a closed-loop current compensation control circuit formed by the motor, current conversion module, current compensation module, vector control module, and motor drive module. The current compensation module adjusts the reference current input to the vector control module to a minimum and make it adjustable. Furthermore, the closed-loop current compensation control circuit automatically adjusts the compensation current under different loads, effectively reducing bus current and phase current, thereby reducing motor overheating and protecting the motor and electric tool from damage due to excessive or unadjustable current.

An electromechanical steering system comprises a first actuator having a first electric motor and a first control unit, and a second actuator having a second electric motor and a second control unit, wherein the first electric motor can be operated in a motor mode or a generator mode depending on the driving situation, wherein the first actuator and the second actuator are communicatively connected to one another, and the second control unit is designed, in a generator mode of the first electric motor, to actuate the second electric motor in such a way that a current that is generated in a generator mode of the first electric motor is converted energetically by the second electric motor, in particular by influencing a Id current for the second electric motor specified by vector control. A method for operating such a steering system in a motor vehicle comprises generating a current in a generator mode of the first electric motor and energetically converting the generated current by the second electric motor.

A vector control method is disclosed in which currents of an electric multiphase machine (183) are represented in a dq-axis coordinate system, comprising the vector control method of injecting a d-axis current based on a q-axis request (140). Furthermore, a corresponding converter and a computer program product are disclosed.