64results about How to "Improve torque control accuracy" patented technology

The invention discloses a fracturing pump, comprising a cooling device and a control device, wherein a motor is connected on an shaft of the fracturing pump, the cooling device comprises an air-cooled device for cooling a rotor of the motor and a water-cooled device for cooling a stator of the motor, and the control device is connected with the motor and the cooling device, respectively. The fracturing pump in the invention adopts a structure directly driven by the motor, thus breaking the form of a transmission structure of a diesel engine of the conventional fracturing pump added with a transmission tank, simplifying the structure of the entire fracturing pump, reducing the apparatus mounted on a fracturing car, decreasing failure rate of the apparatus, and becoming more safe and reliable.

The invention provides a maximum torque control method for a salient-pole permanent-magnet synchronous motor, which is characterized in that vector control on the motor is carried out by a d-axis current instruction id* and a q-axis current instruction iq* under the synchronous rotation coordinate system of a rotor, thus realizing the aim of outputting maximum torque of the motor. Compared with the traditional control method, the maximum torque control method has the advantages of 1) offline calculating current instruction values, controlling in real time by only searching; greatly simplifying real-time operation; and reducing the requirement on the processing capability of a controller; 2) combining a table searching of d-axis current instruction with the precise calculation of q-axis current instruction, thus reducing the error caused by the table searching; and improving torque control precision.

The invention relates to an assisted control system and method based on MCU hill holding and hill starting. The method comprises the following steps of judging whether a vehicle enters a hill-holding mode or not in real time according to a control signal of the vehicle and a motor speed, wherein VCU vehicle operation mode judgment is not needed; after the vehicle enters the hill-holding mode, under the control of the MCU, switching a torque mode to a speed mode; under the speed mode, controlling the speed given to zero speed by the MCU to realize hill holding; in order to achieve zero speed constancy under the speed mode, adjusting output torque by a drive motor according to different gravity components corresponding to different slope angles; and identifying and controlling the entire hill-holding process completely and independently by the MCU, and high precision of torque control and strong real-time capability are achieved.

The invention discloses a combined-type SVPWM (Space Vector Pulse Width Modulation) method. Different SVPWM methods are adopted according to different stator frequencies of an AC motor; when the stator frequency of the AC motor is lower than the low-frequency sector, a half-frequency method is adopted; when the stator frequency of the AC motor is in the medium-and-low frequency sector, a flat-top SVPWM method is adopted; when the stator frequency of the AC motor is in the medium-and-high frequency sector, a seven-segment SVPWM method is adopted; and when the stator frequency of the AC motor is in the high-frequency sector, an FFC (Fundamental Frequency Clocking) SVPWM method. Usually, for power loss of an inverter, the seven-segment SVPWM method is larger than the flat-top SVPWM method, the flat-top SVPWM method is larger than the half-frequency SVPPWM method, and the half-frequency SVPPWM method is larger than the FFC SVPWM method; and for the torque control precision, the four methods are optimal within different frequency ranges. According to the invention, the four SVPWM method are used together, different SVPWM methods are adopted according to different working conditions of the motor so as to play respective potentials; and therefore, lower power loss of the inverter and higher torque control precision are drawn into consideration, and the output power of the motor running in the high-frequency sector is increased.

The invention provides an electric car induction motor torque current setting device. Based on the prior art, a high-speed torque controller, a weighing and calculating module and a torque current setting and calculating module are added. Meanwhile, an existing torque controller used for calculating set torque current is used as a low-speed torque controller. When an induction motor runs at low speed, the low-speed torque controller works, the weight of the low-speed torque controller is set as 1, and torque current i*sq is completely given by the low-speed torque controller. When the induction motor runs at high speed, the high-speed torque controller works, the weight of the high-speed torque controller is set as 1, and the torque current i*sq is completely given by the high-speed torque controller. When the induction motor runs in a switching transition zone, torque current is given by the high-speed torque controller and the low-speed torque controller, and a value of the torque current can be calculated and obtained according to the weight k. When the actual rotation speed of the induction motor increases, slow switching between two structures can be achieved through a slowly-changing weighing method in structural switching, control stability of the induction motor is improved, and torque control accuracy is improved.

The invention provides torque corrosion coefficient calculation and torque analysis methods and systems for an electric automobile. Besides consideration of motor speeds and opening degrees of an accelerator pedal, speeds of the automobile and fault levels are comprehensively considered to determine correction coefficients and correction starting points of torque, and required torque for system analysis is corrected in real time. When the speeds of the automobile and the fault levels are different and the opening degrees of the accelerator pedal are the same, different torque corrosion coefficients can be obtained, and more accurate toque analysis coefficients are obtained; with the adoption of the scheme, more accurate and more comprehensive consideration factors are provided for actual output torque of a motor, and the torque control precision of the whole automobile is improved.

The invention discloses a driving combined steering system, a torque control device and a torque control method. A rotation angle correction module in the driving combined steering system provides an additional rotation angle to a mechanical steering mechanism through a planetary gear mechanism, a steering motor and other mechanisms so as to achieve control over the variable transmission ratio of the steering system. A steering assistance module outputs assistance to the mechanical steering mechanism according to vehicle working conditions through an electric assistance execution mechanism and a hydraulic assistance execution mechanism. Good robustness and assistance tracking performance of the driving combined steering system are achieved.

The invention provides an asynchronous motor rotor time constant on-line identification system. The system comprises a decomposition angle calculation unit, a feedforward voltage decomposition unit, a feedback voltage sampling unit, a feedback voltage decomposition unit and a time constant calculation unit, wherein the decomposition angle calculation unit is used for acquiring a decomposition angle according to exciting current and torque current; the feedforward voltage decomposition unit is used for performing decomposition calculation on the feedforward voltage by using the decomposition angle; the feedback voltage sampling unit is used for sampling the output end of a controlled motor to acquire the feedback voltage; the feedback voltage decomposition unit is used for performing decomposition calculation on the feedback voltage by using the decomposition angle; and the time constant calculation unit is used for calculating and updating the rotor time constant according to the decomposition results of the feedforward voltage and the feedback voltage. The system realizes on-line real-time identification of the rotor time constant through voltage decomposition, and the process is not influenced by the change of stator resistance.

The invention provides an engine accessory torque acquisition method and an engine accessory torque acquisition device. The method includes the steps of accurately acquiring generator demand torque, electrically-controlled fan demand torque, air compression pump demand torque, steering pump demand torque and air conditioning compressor demand torque; performing a summation operation on the generator demand torque, the electrically-controlled fan demand torque, the air compression pump demand torque, the steering pump demand torque and the air conditioning compressor demand torque to obtain accurate demand torque of engine accessories. The precision of the torque in an engine is improved, and the torque control precision of the engine is improved.

The invention discloses an installation mechanism for implementing the installation of a valve rod and a valve body, which comprises a rack and a valve rod locking mechanism arranged on the rack. The valve rod locking mechanism comprises a servo motor fixed on the rack, a fixture which is used for clamping a valve body workpiece and corresponds to the servo motor, a lifting cylinder capable of driving the fixture to ascend and descend, a PLC (Programmable Logic Controller) and a start button; and a rotating shaft which corresponds to a valve rod workpiece and can cause the valve body workpiece and the valve rod workpiece to be screwed down mutually is arranged on the servo motor. The valve rod locking mechanism adopts the servo motor and a clamping lifting mode to implement the locking of the valve body workpiece and the valve rod workpiece. The installation mechanism adopts a manual mode to load and unload materials, adopts the servo motor, the PLC and the electrical control of ascending, descending and the like, implements the man-machine interface operation and is visual and easy to use.

The invention provides a weight-coefficient-free prediction torque control method for a permanent magnet synchronous motor, and the method comprises the following steps: sampling a three-phase current, angular velocity and a rotor position angle of the permanent magnet synchronous motor at a moment k, and obtaining an output current and an equivalent counter electromotive force through coordinatetransformation; calculating the outputted voltage vector and stator voltage according to the switching state of a voltage source inverter, and predicting the output current, the stator flux linkage and the stator flux linkage amplitude and torque at a moment k+1 according to the stator voltage; calculating a torque objective function and a stator flux linkage objective function by using the statorflux linkage amplitude and the torque so as to obtain a new objective function; and finally, comparing the values of the objective functions, and using the voltage vector corresponding to the minimumobjective function to control the permanent magnet synchronous motor. The torque and flux linkage objective function is subjected to two-norm standardization, the method achieves the weight-coefficient-free prediction torque control of the permanent magnet synchronous motor, can reduce the system complexity, reduces torque ripples, and improves the torque control precision.

The invention relates to a control device of electromotor system and relative control method. Said control method comprises: the step (S204) that when there is normal current sensor (the judging result of S202 is yes), calculating the current peak value; the step (S300) that changing the input voltage value; and the step (S400) that changing the carrier wave frequency when the voltage value is not fully modified (the judging result of S214 is no). And the step (S228) that when there is no normal current sensor (the judging result of S202 is no), strengthening the detection of voltage sensor; the step (S400) that changing the carrier wave frequency and the step (S300) that changing the input voltage value when the voltage value is not fully modified (the judging result of S234 is no).

The invention relates to a real-time correction method for a rotor time constant of a three-phase asynchronous motor. An excitation mutual inductance lookup table and a rotor resistance temperature lookup table are established, the excitation mutual inductance Lm is queried according to excitation current, the excitation mutual inductance Lm and the rotor leakage inductance Lsigma are added to obtain the rotor inductance Lr, the rotor resistance Rr is queried according to the stator winding temperature of the motor, namely the rotor temperature, and the rotor time constant can be calculated according to the rotor inductance Lr and the rotor resistance Rr, and thus the real-time correction of the rotor time constant is realized. According to the scheme of the invention, the real-time correction method for the rotor time constant is easy to implement in engineering, the influence of the rotor temperature on the rotor resistance is considered, and the influence of flux saturation on the rotor inductance is also considered; the scheme is not only applicable to the operation area within the base speed of the motor, but also to the high-speed flux weakening area of the motor; and moreover, the rotor time constant of the three-phase asynchronous motor can be corrected in real time, the rotor field orientation accuracy, torque control accuracy, flux weakening control stability and system operation efficiency can be improved, and the dynamic and static performance of vector control can be improved.

The invention relates to an air intake system of a gasoline engine. The air intake system comprises an electric control unit, a pipeline, a turbocharger (1) and a variable valve. The variable valve comprises an intake valve (3) and an exhaust valve (4). The turbocharger (1) comprises an exhaust gas bypass valve (2). The air intake system also comprises an intake switching valve (5) which is placed in a pipeline between the air inlet and the air intake door (3) of the turbocharger (1). The electric control unit controls the intake switching valve (5) to switch between two air inflow modes. During work, air enters into an air cylinder (9) through the air inlet of the turbocharger (1), the intake switching valve (5) and the intake valve (3), and exhaust gas is discharged out of the air cylinder (9) through the exhaust valve (4) and is discharged out of the gasoline engine through the exhaust gas bypass valve (2) and the air outlet of the turbocharger (1). Compared with the prior art, the air intake system of the gasoline engine without a throttle valve reduces the throttling loss caused by the throttle valve body, improves the problem of throttle percentage and nonlinear flow, and improves the torque control precision.

The invention relates to a permanent magnet synchronous motor power compensation control system and method and belongs to the technical field of permanent magnet synchronous motor control. A power compensation adjustment branch circuit is added in an existing control system and used for compensating reference current calculated based on given torque and using compensated reference current to conduct closed-loop control on a permanent magnet synchronous motor, a compensation signal is determined according to a difference value of motor reference electromagnetic power P* and motor feedback electromagnetic power P, the motor reference electromagnetic power P* is calculated according to the given torque and the actual rotation speed of the motor, and the motor feedback electromagnetic power P is calculated according to current acquired in the motor vector control process. The permanent magnet synchronous motor power compensation control system and method achieve the purpose of tracking motor actual power ratio and reference power ratio through reference current compensation, enable motor actual power to completely comply with target power and improve toque control accuracy, and the problem of torque control difference caused by poor consistency of the motor and controller hardware is effectively solved.

The invention discloses a controller of a multi-mode active steering system and a control method of the multi-mode active steering system. The controller is characterized in that coordination control is performed on a plurality of power-assisted actuating mechanisms of the system by taking a system energy consumption function as a control objective, wherein the system energy consumption function comprises motor energy consumption, hydraulic mechanism energy consumption, controller energy consumption and mechanical steering mechanism energy consumption; a sensor module acquires and transmits signals of all parts of the steering system to an energy analysis module; the system energy consumption function is solved by the energy analysis module; a calculated result is transmitted to an electronic control unit; and the electronic control unit performs the coordination control on the power-assisted actuating mechanisms of the system by taking the system energy consumption function as the control objective and taking an ideal power assistance characteristic of the system as a constraint condition. Therefore, steering economy is realized when output power assistance under the constraint condition is ensured to meet an ideal power assistance curve.

The invention discloses a high-precision torque control method for a hybrid power diesel engine. The high-precision torque control method is characterized by comprising the following steps of: acquiring an indication torque, and calibrating to obtain an initial value of oil injection quantity; limiting the initial value of oil injection quantity based on a maximum limit value of accelerated smokeintensity and atmospheric density to obtain a limit value of oil injection quantity; and correcting the fuel injection quantity according to the combustion efficiency and the intercooled temperature to obtain a fuel injection quantity correction value, and controlling the actual fuel injection quantity of the engine to be the fuel injection quantity correction value. Accessory work is added when the indication torque is determined, the accessory work is corrected based on the water temperature of the engine, and the indication torque is more accurate. The fuel injection quantity correction value is obtained by comprehensively considering the influence of various factors, so that under the actual fuel injection quantity, the error between the actually measured flywheel end output torque andthe bus net torque can be reduced, and the torque control precision is improved.

The invention provides a control method and device for torque of an engine. The method is applied to a hybrid power controller of a single-shaft parallel-type hybrid power system. The method comprisesthe steps of determining demand torque of the engine on the condition that the single-shaft parallel-type hybrid power system is in a driving mode; obtaining the current rotation speed of the engine,and determining target correction torque corresponding to the current rotation speed according to predetermined correction torque of the engine under different rotation speeds; correcting the demandtorque according to the target correction torque, and sending the corrected demand torque to an engine controller, so that the engine controller controls the engine to output torque according to the corrected demand torque. Through correction, the difference between the actual output torque of the engine and the distributed demand torque can be reduced, and the precision of controlling the torqueof the engine is improved.

The invention discloses a classification controller of a multi-mode composite steering system and a control method thereof. According to the classification controller of the multi-mode composite steering system and the control method thereof, a working condition feature extraction module is used for processing and analyzing signals input by a sensor module, a classification function is established, and the value of the classification function under the current working condition is calculated. A mode classifier I is used for classifying the steering modes of the steering system into a mode A, a mode B and a mode C; a mode classifier II is used for classifying the mode C into a mode D and a mode E; and a mode classification controller outputs control current to corresponding power module executing mechanisms for driving an electric power executing mechanism and a hydraulic power executing mechanism to output power, thereby realizing the multiple steering mode control function of the system and solving the problem of mode switching of an automotive multi-working mode mechanic-electric-hydraulic coupled power system.

The invention provides a vehicle permanent magnet synchronous motor torque estimation method based on power flow and a medium. The method comprises a motor shaft end output torque calculation step: calculating to obtain the output power of the motor shaft end according to any one parameter or any combination of multiple parameters of the input power of the direct current bus, the power loss of thedirect current busbar, the controller loss, the motor copper loss, the motor iron loss and the friction loss, and calculating to obtain the output torque value of the motor shaft end through the output power of the motor shaft end. According to the method, the actual torque is estimated, the deviation can be calculated with the torque instruction of the vehicle control unit, and torque compensation is carried out, so that higher torque control precision is achieved.