A motor control method and system based on torque feedforward

Abstract

This invention belongs to the field of motor control technology, specifically relating to a motor control method and system based on torque feedforward. The method includes: constructing a wide-area network spatiotemporal topology matrix to capture spatially distributed digital service scheduling commands; calculating the dynamic transient propagation delay of pressure pulse waves by combining the intrinsic sound velocity and convection velocity of the fluid; constructing an effective flow area function for a single unit based on the action timestamp and the target opening change; reconstructing the time-series equivalent network flow area by combining the hydraulic contribution weight coefficient; using this to deduce a dynamic feedforward torque reference; extracting the integral of the torque trajectory deviation for fault-tolerant monitoring; and converting the torque reference into a feedforward quadrature-axis current quantity which is directly injected into the current inner loop to execute feedforward control. This invention comprehensively considers the hydraulic propagation delay and valve action time, overcoming the drive mismatch defect caused by the asynchronous issuance of commands and actual force, and can promptly identify valve jamming faults.

Description

Technical Field

[0001] This invention relates to the field of motor control technology. More specifically, this invention relates to a motor control method and system based on torque feedforward. Background Technology

[0002] In urban centralized heating and smart water management pipeline engineering practices, the circulating water pumps of secondary heat exchange pumping stations are typically controlled by motors driven by vector frequency converters to maintain the hydraulic balance of the pipeline network. When numerous terminal intelligent electronically controlled valves in the pipeline network frequently adjust their opening, the contraction or expansion of the total effective flow area of ​​the pipeline network can cause severe transient changes in hydraulic resistance. To overcome the lag of traditional proportional-integral controllers, the industry typically employs feedforward compensation technology, which converts relevant control commands or operating states into motor torque compensation quantities in advance, aiming to proactively intervene before changes in physical resistance occur.

[0003] Chinese patent document CN114915217B describes a control method for a permanent magnet synchronous motor based on load torque compensation. This method utilizes a load torque observer to monitor the load torque; automatically adjusts the feedback gain based on the changes in the given load torque and the observed load torque; and converts the observed load torque into a torque current compensation component, which is then fed forward to the input of the q-axis current PI controller. However, this patent relies heavily on the observer for post-event torque state tracking. In long-distance fluid pipelines, when hydraulic fluctuations caused by the action of remote valves are transmitted to the pumping station over long distances, this method, dependent on local motor state observation, suffers from response lag and cannot perform feedforward actions based on pre-issued digital commands from the host computer, making it difficult to cope with sudden water hammer effects in long-distance pipelines.

[0004] Chinese patent document CN107070335B discloses a torque feedforward control method for a dual-PWM permanent magnet electric drive system. This method obtains the load torque observation value based on the angular velocity and stator current at the motor output. Based on the principle of equal power, it converts the motor load torque to the corresponding output torque at the generator end. It then calculates the given torque current at the generator end to obtain the pulse width modulation control signal. However, this patent document directly converts the mechanical torque value into an equivalent electromagnetic drive command. This numerical mapping does not consider the mechanical hysteresis characteristics of physical equipment operation and the time delay due to spatial distance. When an external control command is issued, the frequency converter quickly changes the electromagnetic torque, while the physical valve's operation has a mechanical delay, causing a time misalignment between the motor's electromagnetic drive force and the actual mechanical resistance.

[0005] Chinese patent document CN108462413B discloses a motor control device and method. It sets any value from 0 to 1 as a compensation coefficient; multiplies the torque compensation value (which suppresses periodic changes in motor speed) by this compensation coefficient and adds the results to the torque command to obtain the compensated torque command; and derives a speed compensation value based on the torque compensation value and the compensation coefficient, then corrects the speed command based on this speed compensation value. However, this patent document only adjusts the torque command by multiplying and adding a fixed proportional coefficient, lacking a monitoring mechanism for the actual execution status of external physical layer equipment. In actual pipeline environments, remote valves are prone to mechanical failure due to scaling and jamming. If the system directly executes torque compensation based on digital commands, it will change the inverter output even if the actual area of ​​the physical pipeline network has not changed, potentially leading to motor stall and shutdown.

[0006] In existing technologies, although some solutions attempt to achieve torque feedforward and compensation control of motors through load observers, power conversion, or setting proportional coefficients, these solutions are mostly limited to electromagnetic and mechanical state calculations within the electrical control system, or treat external digital scheduling commands directly as real-time physical constraints. Because real physical heating networks inevitably experience mechanical delays when executing commands—such as the slow movement of valve cores driven by miniature DC motors inside valves, and the time delay of hydraulic fluctuations propagating over long distances—digital commands and the underlying physical execution state become severely disconnected in time and space. Furthermore, in practical applications, when remote physical valves become stuck due to scaling or other reasons, the digital commands issued by the host computer become false commands that contradict the physical reality. Existing motor drive control methods, if they directly execute digital commands or rely solely on local state observation, cannot identify command failures caused by physical faults in advance, easily leading to mismatches between electromagnetic drive loads and actual hydraulic resistance, thus affecting the operational stability of high-flow-rate pumping circulation systems under complex network scheduling. Summary of the Invention

[0007] To address the technical problem of drive mismatch caused by the disconnect between digital command stream and the actual hydraulic load state of the physical pipe network in existing motor feedforward control, this invention provides solutions in the following aspects.

[0008] In a first aspect, the present invention provides a motor control method based on torque feedforward, comprising: constructing a wide-area network spatiotemporal topology matrix and capturing spatially distributed digital service scheduling instruction data; calculating the actual total network span of each terminal intelligent electric control valve according to the wide-area network spatiotemporal topology matrix, and obtaining the intrinsic sound velocity of the fluid and the real-time macroscopic convection velocity of the fluid, constructing a fluid acoustic-flow coupling transient delay model, and analyzing the arrival time window of the pressure pulse wave to obtain the dynamic transient propagation delay; constructing a single effective flow area function characterizing the change of the effective flow cross section of a single terminal intelligent electric control valve with time based on the action timestamp and the target opening change, and calculating the hydraulic contribution weight of each pipeline branch. The coefficients, combined with the dynamic transient propagation delay, are used to perform time-shifting and spatial weighted summation on the effective flow area function of each individual unit to establish a spatiotemporal distributed delay model. This model reconstructs and obtains the time-series equivalent network flow area, which characterizes the overall equivalent flow cross-section of the entire network. The time-series equivalent network flow area and the drive motor feedback parameters are used to deduce the pre-simulation equation to obtain the dynamic feedforward torque reference. Based on the dynamic feedforward torque reference and the actual electromagnetic torque, a torque trajectory deviation integral is constructed for system fault tolerance monitoring. The dynamic feedforward torque reference is converted into a feedforward quadrature-axis current and injected directly into the current inner loop as a high-priority bypass command to control the output compensation electromagnetic torque of the drive motor.

[0009] This invention constructs a wide-area network spatiotemporal topology matrix and combines it with a fluid acoustic-flow coupling transient time delay model to transform dispersed control commands into corresponding flow area changes. These changes are then combined with drive motor feedback parameters to deduce a dynamic feedforward torque benchmark, which is finally converted into a current command and directly injected into the current inner loop. In the process of generating the feedforward control command, this invention introduces the time delay of water flow propagation and the physical time consumption of valve mechanical actions. This ensures that the time node of the final drive motor output compensation torque matches the actual time node of the network hydraulic fluctuations reaching the pump, solving the drive misalignment problem caused by directly controlling the motor based on digital commands. Furthermore, by calculating the integral of the deviation between the predicted torque and the actual torque, the system can promptly identify whether remote valves are jammed, thereby preventing the drive motor from stalling under erroneous commands and ensuring the stable operation of the entire heating network system.

[0010] Preferably, the spatially distributed digital service scheduling instruction data includes: action timestamp, initial absolute opening angle, target absolute opening angle, and target opening change.

[0011] Preferably, obtaining the dynamic transient propagation delay includes: calculating the sum of the fluid intrinsic sound velocity and the real-time fluid macroscopic convection velocity as the wave velocity, calculating the ratio of the actual total span of the pipeline network to the wave velocity, and obtaining the dynamic transient propagation delay generated by the terminal intelligent electronic control valve.

[0012] Since the propagation of pressure waves in pipelines is affected by the water flow velocity and physical distance, this invention combines the intrinsic sound velocity of the fluid, the macroscopic convection velocity of the fluid, and the actual total span of the pipeline network to obtain the dynamic transient propagation time delay. This allows for the accurate reconstruction of the actual time required for the hydraulic damping generated by the action of the remote valve to be transmitted to the shaft end of the circulating water pump, providing a time reference for the precise delay compensation of subsequent control commands.

[0013] Preferably, the step of constructing a single-unit effective flow area function representing the change of the effective flow cross section of a single terminal intelligent solenoid valve over time based on the action timestamp and the target opening change includes: obtaining the valve core mechanical angular velocity of the micro DC motor inside the terminal intelligent solenoid valve; calculating the absolute value of the target opening change, dividing the absolute value by the valve core mechanical angular velocity to obtain the full stroke execution time; constructing a piecewise function of the real-time opening angle based on the initial absolute opening angle, the target absolute opening angle, the action timestamp, the full stroke execution time, and the valve core mechanical angular velocity; obtaining the inherent flow coefficient based on the factory technical parameter book of the terminal intelligent solenoid valve, and constructing a valve core cross section mapping function based on its inherent flow characteristic curve; and using the inherent flow coefficient, the valve core cross section mapping function, and the piecewise function of the real-time opening angle to deduce the single-unit effective flow area function.

[0014] This invention uses the mechanical parameters of a micro DC motor to calculate the full stroke execution time of a valve, and thereby constructs a piecewise function of the real-time opening angle and a single effective flow area function. In actual working conditions, the valve opening is slowly changed by the motor drive, transforming the step-like scheduling command into a slowly changing displacement trajectory that conforms to the real mechanical transmission law, which can reflect the gradual change process of the flow area of ​​a single valve.

[0015] Preferably, the hydraulic contribution weight coefficient of each pipeline branch is calculated, and the effective flow area function of each individual unit is time-shifted and spatially weighted summed in combination with the dynamic transient propagation delay to establish a spatiotemporal distributed delay model. The time-series equivalent network flow area representing the comprehensive equivalent flow cross section of the entire network is reconstructed. This includes: extracting the product of the pipe cross-sectional area of ​​the corresponding pipeline branch in the spatiotemporal topology matrix of the wide-area pipeline network and the rated design flow velocity to obtain the design volumetric flow rate; calculating the proportion of the volumetric flow rate in the total heating flow of the entire network, and setting it as the hydraulic contribution weight coefficient; using the hydraulic contribution weight coefficient, performing a backward translation geometric mapping operation on the effective flow area function of each individual unit on the time coordinate axis with a time length equal to the dynamic transient propagation delay, and performing a matrix spatial weighted summation operation at the current moment to obtain the time-series equivalent network flow area.

[0016] This invention establishes hydraulic contribution weighting coefficients based on the design volumetric flow rate of each pipeline, and combines dynamic transient propagation delay to translate and spatially weight and sum the effective flow area functions of each individual unit on the time axis. Faced with numerous unevenly distributed valves in the pipeline network, this calculation method integrates the asynchronous flow cross-sectional change characteristics of different nodes into the comprehensive equivalent flow area borne by the pump station, providing global data that conforms to the actual situation for calculating feedforward torque.

[0017] Preferably, the formula for calculating the dynamic feedforward torque reference is: In the formula, This is the system clock time; For a moment Dynamic feedforward torque reference; It is the resistance constant; To improve overall conversion efficiency; For a moment The time-equivalent network circulation area; For target loop flow; For a moment The mechanical angular velocity of the drive motor.

[0018] In deriving the dynamic feedforward torque reference, this invention correlates the system resistance constant, overall conversion efficiency, target circulating flow rate, mechanical angular velocity of the drive motor, and time-series equivalent network flow area for calculation. This derivation process is based on the physical laws of pipeline pressure drop and flow rate in fluid mechanics, as well as the conversion mechanism of pump mechanical power. When the equivalent flow area of ​​the pipeline decreases, causing an increase in resistance, the calculated feedforward torque reference will increase accordingly, enabling the control end to obtain the compensation torque required to cope with the change in resistance in advance, thereby maintaining the power balance of the system.

[0019] Preferably, the construction of the torque trajectory deviation integral includes: obtaining the shortest dynamic transient propagation delay included in the full network pipeline branch delay calculation results. With the longest dynamic transient propagation delay Combined with the global maximum full-process execution time With action timestamps As the starting offset point, construct the deviation monitoring time integration observation window. Within the deviation monitoring time integration observation window, the absolute value of the difference between the real electromagnetic torque and the dynamic feedforward torque reference is accumulated over a time infinitesimal element to extract the torque trajectory deviation integral.

[0020] This invention combines the shortest and longest dynamic transient propagation delays and the full-stroke execution time to define a deviation monitoring time integration observation window. Within this observation window, the absolute value of the difference between the actual electromagnetic torque and the dynamic feedforward torque reference is accumulated by definite integration, which can effectively filter out interference during periods without fluctuations. If the cumulative deviation between the actual torque and the predicted torque continues to increase within this window, it indicates that the pipeline resistance has not changed as expected, thus providing data indicators for judging whether the remote valve is stuck.

[0021] Preferably, the system fault tolerance monitoring includes: setting a tolerance safety integral threshold; when the integral amount of the torque trajectory deviation exceeds the tolerance safety integral threshold, determining that the current pipeline branch has a mechanical jamming failure of the terminal intelligent electronic control valve, interrupting the pre-evolution equation and cutting off the feedforward torque transmission link path, switching back to the constant torque steady-state control strategy based on pressure sensor feedback, and reporting an alarm message for system equipment pipeline failure to operate.

[0022] Preferably, the dynamic feedforward torque reference is converted into a feedforward quadrature-axis current and directly injected into the inner current loop as a high-priority bypass command to control the output compensation electromagnetic torque of the drive motor. This includes: extracting the electromagnetic torque mapping transformation constant coefficients fixed at the factory of the drive motor; dividing the dynamic feedforward torque reference by the electromagnetic torque mapping transformation constant coefficients to generate a feedforward quadrature-axis current; extracting the feedforward quadrature-axis current in the logic scan cycle of the dual closed-loop field-oriented decoupling control algorithm at the bottom layer of the frequency converter main control chip and introducing it into the frequency converter operation logic node; performing a digital parallel arithmetic superposition and summation operation with the feedback current reference output from the speed outer loop in the inner high-speed logic adder; generating a total current reference command that bypasses the low-speed integrator and is introduced into the high-frequency response execution comparison inner loop; using the total current reference command to drive the full-bridge hardware power switch module to perform voltage inverter chopper modulation to output a high-frequency alternating current; controlling the drive motor stator to synchronously establish a compensation electromagnetic torque with the same amplitude and opposite direction as the external transient mechanical load torque at the same time node when the pressure pulse wave arrives at the end face of the circulating water pump mechanically doing work.

[0023] This invention introduces the converted feedforward quadrature shaft current into the frequency conversion operation logic node, directly bypassing the low-speed integrator and entering the high-frequency response current inner loop. Since the response of the outer mechanical speed regulation loop has inherent hysteresis, directly injecting the feedforward command into the current loop can significantly shorten the control response cycle, enabling the motor stator to output a compensating electromagnetic torque that matches the external transient load with extremely low delay, thereby maintaining the force balance at the mechanical shaft end.

[0024] In a second aspect, the present invention provides a motor control system based on torque feedforward, including a processor and a memory, wherein the memory stores computer program instructions, and when the computer program instructions are executed by the processor, the aforementioned motor control method based on torque feedforward is implemented.

[0025] By adopting the above technical solution, a computer program is generated from the above-mentioned motor control method based on torque feedforward and stored in the memory so that it can be loaded and executed by the processor. In this way, a terminal device can be made based on the memory and the processor for convenient use.

[0026] The beneficial effects of this invention are as follows:

[0027] 1. When analyzing pipeline control commands, this invention takes into account the physical propagation delay of water flow pressure waves and the mechanical action time of the valve core driven by the micro DC motor. By introducing spatial weight and time translation mechanism, the area changes of each dispersed valve are integrated into a globally equivalent flow area. This scheme restores the time-sequential equivalent load of the superimposed physical actions of multiple nodes transmitted to the bottom pump station, and overcomes the time misalignment problem between network command issuance and actual hydraulic response.

[0028] 2. Based on the system's hydraulic dynamic conversion mechanism, this invention substitutes the reconstructed time-series equivalent network flow area into the underlying mechanical relationship to deduce the dynamic feedforward torque benchmark, and converts it into a feedforward quadrature axis current that is directly injected into the inverter's inner current loop. This bypasses the response time-limited outer mechanical speed integral adjustment loop, enabling the drive motor to quickly and synchronously output the required compensation torque before the pipeline resistance actually reaches the pump, thus improving the system's dynamic adjustment capability in response to hydraulic transients.

[0029] 3. This invention utilizes the shortest delay, the longest delay, and the full stroke time to set the deviation monitoring time integration observation window. Within the core range of hydraulic wave disturbance, it continuously calculates the cumulative deviation between the actual hardware execution torque and the expected consumed torque. When this deviation exceeds the tolerance safety integration threshold, the system can accurately identify mechanical jamming and failure to operate faults, and promptly block the erroneous guidance of the failed action intention to the control command, preventing the drive motor from stalling under abnormal loads, and effectively ensuring the operational safety of pipeline equipment. Attached Figure Description

[0030] Figure 1 This is a flowchart illustrating a motor control method based on torque feedforward according to the present invention. Detailed Implementation

[0031] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0032] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0033] This invention discloses a motor control method based on torque feedforward, referring to... Figure 1 This includes steps S1-S5:

[0034] S1. Construct a spatiotemporal topology matrix for the wide-area network and capture spatially distributed digital service scheduling instruction data.

[0035] To establish a precise mapping benchmark between digital signal command streams and the physical underlying hydraulic boundary state, this invention analyzes the control action commands of the terminal intelligent electric control valve on the upper computer control side and integrates the three-dimensional geospatial attribute data of the pipeline network. This transforms the spatially dispersed and time-asynchronous independent control signals into regularized array data with precise timestamps and spatial coordinates, thereby providing data support for subsequent calculations of the propagation path and arrival time of pressure pulse waves.

[0036] Specifically, through the digital communication bus protocol layer of the smart heating software platform, the spatial geographic three-dimensional positioning coordinates, pipe cross-sectional area, and rated design flow velocity of all terminal intelligent electric control valves equipped with independent communication node addresses within the physical space of the pipeline network are obtained. The reference three-dimensional coordinates of the central pump station are extracted, and the above static parameters are entered into the memory space of the server. A wide-area pipeline spatiotemporal topology matrix representing the hot water supply hydraulic layout is established. Through the data monitoring port mounted on the digital communication bus, the message data packets sent by the system to each terminal intelligent electric control valve are monitored in real time, and the action timestamp, initial absolute opening angle, target absolute opening angle, and target opening change of each discrete terminal intelligent electric control valve are extracted from them.

[0037] Furthermore, the extracted action timestamps, initial absolute opening angles, target absolute opening angles, and target opening changes are indexed by the unique identifiers of the communication node addresses and filled into the virtual spatial nodes within the spatiotemporal topology matrix of the wide area network, thus completing the capture and parameter alignment of spatially distributed digital service scheduling instruction data.

[0038] S2. Calculate the actual total span of the intelligent electronic control valves at each terminal based on the spatiotemporal topology matrix of the wide-area pipeline network, obtain the intrinsic sound velocity of the fluid and the real-time macroscopic convection velocity of the fluid, construct a fluid acoustic-flow coupled transient delay model, and analyze the arrival time window of the pressure pulse wave to obtain the dynamic transient propagation delay.

[0039] The sudden change in hydraulic resistance in a fluid pipeline system is not instantaneously applied to the shaft end of the circulating water pump at the far end with the change in terminal opening. The physical propagation mechanism of transient pressure disturbance in the liquid circular pipe follows the one-dimensional micro-amplitude fluctuation continuity equation and the elastic water hammer dynamics theory. The propagation speed of the pressure pulse wave in the viscous fluid medium is dominated by the intrinsic sound speed of the fluid and is modulated by the linear Doppler effect of the real-time macroscopic convection velocity of the fluid. Based on the above physical laws, this invention constructs a fluid acoustic-flow coupling transient time delay model, which aims to determine the physical transmission time of the pressure pulse wave caused by the adjustment action of each independent terminal across the long-distance physical pipeline and actually transmitted to the shaft end of the circulating water pump, so as to obtain the mechanical displacement time parameter and the sound wave transmission time parameter.

[0040] Specifically, in the spatiotemporal topology matrix of the wide-area pipeline network, the spatial distance algorithm combined with the pipeline wiring ledger is used to calculate the total actual pipeline laying length between the spatial geographic three-dimensional positioning coordinates of each terminal intelligent electric control valve and the reference three-dimensional coordinates of the central pump station. This total actual pipeline laying length is defined as the total span of the actual pipeline network. The current water temperature is obtained by the temperature sensor installed on the heating main pipeline of the central pump station. Based on the water temperature, the built-in medium property parameter table is consulted to determine the fluid intrinsic sound velocity of the pressure pulse wave at the current water temperature. Based on the current water temperature, the built-in medium property parameter table is consulted to determine the fluid density. By obtaining the flow sensor data of the pipeline branch where the terminal intelligent electric control valve is located and dividing it by the cross-sectional area of ​​the pipeline corresponding to that pipeline branch, the real-time macroscopic convection velocity of the fluid inside each pipeline branch is calculated.

[0041] Furthermore, in a static fluid medium, the pressure pulse wave triggered by the opening adjustment of the terminal intelligent electronic control valve propagates mechanically forward at the fluid's intrinsic sound speed. When the heating hot water carrying medium inside the pipe flows directionally at a predetermined flow rate, the actual physical propagation speed of this pressure pulse wave relative to the external static physical reference wall of the pipe is equal to the superposition of the fluid's intrinsic sound speed and the real-time macroscopic convection velocity of the fluid. That is, the wave velocity calculation formula is constructed as follows: , For the intrinsic speed of sound of the fluid, For the first The real-time macroscopic convection velocity of the fluid within each pipeline branch; based on the displacement and time constraint principle in fundamental kinematics, the motion time consumed by the pressure pulse wave across space satisfies the linear distance relationship equation, i.e. , For the first The actual total span of the pipeline network between the terminal intelligent electronic control valve and the central pumping station. For the first The dynamic transient propagation delay generated by a terminal intelligent electronic control valve; substituting the wave velocity calculation formula completely into the linear distance relationship equation, replacing the actual physical propagation speed variable, and then deriving the calculation formula for the dynamic transient propagation delay, the calculation formula for the dynamic transient propagation delay is:

[0042]

[0043] In the formula, For the first Dynamic transient propagation delay generated by a terminal intelligent electronically controlled valve; For the first The actual total span of the pipeline network between each terminal intelligent electronic control valve and the central pump station; The intrinsic speed of sound in the fluid; For the first Real-time macroscopic convection velocity of fluid within each pipeline branch.

[0044] The calculation formula incorporates sound velocity attenuation characteristics, Doppler frequency shift characteristics, and physical routing distance of pipeline branches into the time dimension estimation. Based on the spatiotemporal data flow link, the increase in the actual total span of the pipeline network leads to a larger dynamic transient propagation delay, which means that the hydraulic resistance generated by the action of the remote terminal intelligent electric control valve needs a longer physical time to be transmitted to the shaft end of the circulating water pump. Through this data mapping relationship, the spatiotemporal misalignment interference between the instantaneous delivery of communication commands in the digital control system and the actual physical hydraulic delay is effectively eliminated.

[0045] S3. Construct the effective flow area function of a single unit based on the action timestamp and the target opening change, calculate the hydraulic contribution weight coefficient of each pipeline branch, establish a spatiotemporal distributed delay model, and reconstruct to obtain the time-series equivalent network flow area.

[0046] Large-scale heating pipe networks are interconnected in a vast three-dimensional space with numerous terminal intelligent electrically controlled valves at varying pipeline distances. The pressure pulse waves generated by their actions reach the central pumping station at different times across different lengths. At the boundary of the circulating water pump shaft, these pulse waves collectively exhibit a force effect resulting from the overlapping and fusion of multiple time-gradient pressure pulse waves. This invention aggregates the geometric flow cross-sectional variation characteristics of the discretely distributed and asynchronously arriving components of the entire network into a single time-series equivalent network flow area parameter by synchronously translating the physical delay attribute on the one-dimensional time coordinate with the valve opening attribute on the three-dimensional spatial topology and weighting it with flow distribution.

[0047] Specifically, based on the factory nameplate parameters of the terminal intelligent solenoid valve, the rated speed of the internal micro DC motor and the mechanical reduction ratio of the gearbox are obtained. The rated speed is then divided by a constant 60 and multiplied by a constant. Then, divide the calculation result by the mechanical reduction ratio to obtain the valve core mechanical angular velocity under the international standard physical dimensions; calculate the absolute value of the target opening change, divide the absolute value by the valve core mechanical angular velocity, and obtain the corresponding full stroke execution time.

[0048] Furthermore, a piecewise function for the real-time opening angle is constructed based on the initial absolute opening angle, the target absolute opening angle, the action timestamp, the full stroke execution time, and the valve core mechanical angular velocity. Its calculation formula is as follows:

[0049]

[0050] In the formula, For the first Each terminal intelligent electronically controlled valve changes with the system clock time. The changing real-time opening angle; This is the initial absolute opening angle; A sign function for determining the direction of motion; For the first The target absolute opening angle of the intelligent electronically controlled valve at the terminal; For the first The mechanical angular velocity of the valve core of a terminal intelligent electronically controlled valve; This is the system clock time; For action timestamps; For the first The full stroke execution time of an intelligent electronically controlled valve at a terminal.

[0051] Among them, the action direction discrimination sign function The specific judgment logic is as follows: when When, the output value is 1; when When, the output value is -1; when When the value is 0, the output value is 0. The value output by this function specifies the polarity of the increase or decrease of the valve core mechanical displacement, so that the piecewise function of the real-time opening angle can adapt to the bidirectional adjustment condition of the terminal intelligent electric control valve when it is opening or closing.

[0052] In this calculation formula, the time varies with the system clock. The increase in action timestamps Full trip execution time Real-time opening angle within the time window of superimposed constraints valve core mechanical angular velocity A fixed slope that increases or decreases linearly means that the valve core is performing a slow and continuous physical displacement operation driven by a miniature DC motor, when the system clock time... Once the full stroke execution cycle boundary is exceeded, the real-time opening angle is clamped and locked to keep the target absolute opening angle constant, which means that the physical and mechanical displacement within this action cycle has completely ended.

[0053] Furthermore, based on the factory technical parameter booklet of the terminal intelligent electric control valve, the inherent flow coefficient is obtained. Based on its inherent flow characteristic curve, a valve core section mapping function is constructed, and the inherent flow coefficient is determined. This refers to the flow rate of room temperature water when fully open under a pressure difference of 1 bar. The inherent flow characteristic curve represents the relationship between the opening angle and the flow rate percentage. Using the inherent flow coefficient, valve core section mapping function, and real-time opening angle, the effective flow area function of the terminal intelligent solenoid valve at the end of each pipeline branch, varying with the system clock time, is derived. Its calculation formula is:

[0054]

[0055] In the formula, This is the system clock time; For the first Each terminal intelligent electronically controlled valve changes with the system clock time. The varying effective flow area function of a single unit; For the first The inherent flow coefficient of an intelligent electronically controlled valve at a terminal; For the first The valve core cross-section mapping function of a terminal intelligent electronically controlled valve; For the first Each terminal intelligent electronically controlled valve changes with the system clock time. The changing real-time opening angle.

[0056] In this calculation formula, the real-time opening angle is... Changes cause the valve core section mapping function to change The output area reference value produces a non-linear change, which in turn affects the inherent flow coefficient. Multiplication results in the effective flow area function of a single unit. The change in the output value means that the mechanical rotation and displacement process synchronously changes the passable cross-sectional area at the current physical location of the pipeline node.

[0057] Furthermore, the cross-sectional area and rated design velocity of the corresponding pipeline branch in the spatiotemporal topology matrix of the wide-area pipeline network are extracted. The design volumetric flow rate of the pipeline branch is calculated by multiplying the cross-sectional area and the rated design velocity. The design volumetric flow rate of the pipeline branch is then divided by the comprehensive cumulative value of the design volumetric flow rates of all pipeline branches in the entire network to obtain the proportion of the volumetric flow rate of the pipeline branch in the total heating flow of the entire network. This proportion of volumetric flow rate is set as the hydraulic contribution weighting coefficient characterizing the load share of the pipeline branch.

[0058] Furthermore, using the obtained hydraulic contribution weighting coefficients, a backward geometric mapping operation is performed on the effective flow area function of each individual cell on the time axis, with a time length equal to the dynamic transient propagation delay. Then, all the translated and scaled function results are subjected to a matrix-space weighted summation operation at the current moment to obtain the time-series equivalent network flow area, calculated as follows:

[0059]

[0060] In the formula, This is the system clock time; For a moment The time-equivalent network circulation area; This represents the total number of terminal intelligent electronically controlled valves in the spatiotemporal topology matrix of the wide-area pipeline network; This refers to the serial number of the terminal intelligent electric control valve; For the first Hydraulic contribution weighting coefficient of each terminal intelligent electronic control valve in the pipeline branch; For the first Each terminal intelligent electronically controlled valve at any time The effective flow area function of a single unit, i.e., the first The terminal intelligent electronic control valve experienced dynamic transient propagation delay. The effective flow area function of each subsequent historical unit.

[0061] The calculation formula, based on the spatial weighting of pipeline branches and the physical time delay mechanism of pipelines, reflects the comprehensive flow cross-sectional variables acting on the mechanical shaft of the circulating water pump unit across physical pipelines. The constructed time-series equivalent network flow area exhibits a step-by-step change characteristic that conforms to the fluid dynamic dissipation process. Through this time-series data, the asynchronous evolution process of the impedance state of long-distance physical pipeline network is restored, providing a force boundary data benchmark that is accurately aligned on the time axis for subsequent torque compensation.

[0062] S4. Using the time-equivalent network flow area and drive motor feedback parameters, the basic control equations are derived to obtain the dynamic feedforward torque reference. Based on the dynamic feedforward torque reference and the real electromagnetic torque, the torque trajectory deviation integral is constructed for system fault-tolerant monitoring.

[0063] For long-distance closed-loop fluid pipeline systems, this invention converts the reconstructed time-equivalent network flow area into a dynamic feedforward torque reference on the output shaft of the drive motor through a system hydraulic dynamic conversion mechanism, establishing a low-level mechanical mapping relationship model. Furthermore, for the fault condition of valve core jamming and refusal to operate due to scaling in the physical pipeline network, this invention introduces an integral evaluation mechanism based on the difference between the dynamic feedforward torque reference and the actual electromagnetic torque. By calculating the cumulative deviation between the actual hardware execution torque and the expected fluid dynamic consumption torque, this invention achieves the identification and control protection of valve refusal to operate faults in the remote pipeline network.

[0064] Specifically, in a closed-loop fluid network, the total system pressure drop With fluid volume flow rate The square of the equation is proportional to the mapping relationship, and its fundamental mechanical equation is expressed as follows: , The comprehensive resistance number is the overall resistance of the pipeline network; based on the one-dimensional continuity loss characteristics of fluid passing through obstructed components, the comprehensive resistance number... Equivalent network circulation area with time sequence The square of is inversely proportional, that is, the equation is: , Where is the drag constant. , This refers to the local drag coefficient, which is calibrated offline and pre-stored during the deployment phase. Let the fluid density be ; Substituting the expression for the overall drag number into the fundamental mechanical equations to eliminate the variable of the overall drag number, we obtain the explicit expression for the total pressure drop of the system as follows: Based on the mechanical work conversion law of centrifugal pumps, the hydraulic power of the fluid medium Equal to the total system voltage drop With fluid volume flow rate The product of, i.e. The equation for calculating hydraulic power is derived as follows: The overall conversion efficiency is obtained based on the parameters on the manufacturer's equipment nameplate of the circulating water pump. The mechanical shaft power applied to the pump shaft by the drive motor equals hydraulic power divided by overall conversion efficiency ,Right now Substituting the numerator of the hydraulic power calculation equation into the mechanical shaft power relation and performing fractional simplification, we obtain the mechanical shaft power expression as follows: The mechanical angular velocity of the drive motor is obtained in real time through the encoder feedback channel of the drive motor. In the rotational rigid body mechanics of a drive motor, the mechanical shaft power is equal to the dynamic feedforward torque reference. With the mechanical angular velocity of the motor The product of, i.e. Substituting the derived expression for the mechanical shaft power into the left side of the torque balance equation, we construct the cross-domain physical field parameter relationship as follows: .

[0065] Furthermore, both sides of this equation are simultaneously divided by the mechanical angular velocity of the drive motor. The operation separates the dynamic feedforward torque reference and replaces the fluid volumetric flow rate in the formula variables with the target circulating flow rate uniformly scheduled by the system. The fundamental governing equations are derived as follows:

[0066]

[0067] In the formula, This is the system clock time; For a moment Dynamic feedforward torque reference; It is the resistance constant; To improve overall conversion efficiency; For a moment The time-equivalent network circulation area; For target loop flow; For a moment The mechanical angular velocity of the drive motor.

[0068] In this calculation formula, the time-equivalent network flow area Reducing the value leads to a decrease in the denominator parameter, including the squared term, resulting in a larger calculation result. (Dynamic feedforward torque reference) As the opening of the remote valve decreases, the physical resistance increases, requiring the underlying control to increase the compensation torque output at a constant speed to meet the power balance requirements.

[0069] Furthermore, by using vector acquisition and calculation from the inverter's underlying current Hall sensor, the actual electromagnetic torque output of the drive motor's closed-loop control loop at the current moment is analyzed; the shortest and longest dynamic transient propagation delays included in the branch delay calculation results of the entire pipeline network are obtained, and the global maximum full-stroke execution time is extracted based on the maximum full-stroke execution time of all terminal intelligent electronic control valves. Using the action timestamp of the same batch of control commands as the starting offset point, a deviation monitoring time integration observation window is constructed to cover the hydraulic wave disturbance range. Within this deviation monitoring time integration observation window, the absolute value of the dynamic difference between the actual electromagnetic torque and the dynamic feedforward torque reference is accumulated over a time infinitesimal element to extract the torque trajectory deviation integral, the calculation formula of which is:

[0070]

[0071] In the formula, This is the integral of the torque trajectory deviation; For action timestamps; For the shortest dynamic transient propagation delay; This is the longest dynamic transient propagation delay; This represents the global maximum full-stroke execution time. For a moment The actual electromagnetic torque; For a moment Dynamic feedforward torque reference; It is a time integral infinitesimal element.

[0072] In this calculation formula, the actual electromagnetic torque Deviation from dynamic feedforward torque reference The increased degree of deviation leads to a larger absolute value of the residual of the integrand, which in turn leads to a larger integral of the torque trajectory deviation calculated over time. The increase means that after the host computer issues digital action commands, the expected change in hydraulic resistance occurs in the pipeline, and the mechanical load actually borne by the drive motor does not respond to the scheduling command.

[0073] Furthermore, based on an empirical value between 5% and 10% of the total integral of the reference torque corresponding to the same time integral length under the system's rated torque operating state, a tolerance safety integral threshold is set; when the torque trajectory deviation integral calculated by the monitoring module... When the tolerance safety integral threshold is exceeded, the underlying control chip determines that the terminal intelligent electric control valve of the current pipeline branch has mechanical jamming and failure to operate. The control actuator interrupts the basic control model and cuts off the feedforward torque transmission link, switching back to the constant torque steady-state control strategy based on pressure sensor feedback to maintain system pressure circulation and prevent motor stall. At the same time, it reports the system equipment pipeline failure to operate abnormal alarm message to the host computer scheduling and management module through the communication protocol.

[0074] S5. Convert the dynamic feedforward torque reference into a feedforward quadrature-axis current quantity and inject it directly into the current inner loop as a high-priority bypass command, and execute the spatiotemporally aligned feedforward output to reconstruct the vector control loop.

[0075] Traditional industrial vector inverter architectures rely on the mechanical speed error feedback loop inside the drive motor to generate compensation and adjustment commands. This calculation logic based on speed error feedback causes the system to exhibit control hysteresis when dealing with load disturbances. This invention, through the above model derivation, generates target command variables that include time translation constraints and physical state constraints. These command parameters are directly input into the inverter's underlying current loop, bypassing the response time-constrained outer proportional error integral loop.

[0076] Specifically, the electromagnetic torque mapping transformation constant coefficients of the drive motor, which are factory-fixed, are extracted from the system hardware memory; the calculated dynamic feedforward torque reference is divided by the electromagnetic torque mapping transformation constant coefficients, and a scaling conversion calculation from mechanical torque dimensions to current given response dimensions is performed to generate a feedforward quadrature-axis current with a corresponding target drive amplitude.

[0077] Furthermore, through the field communication hardware bus port of the high-performance vector inverter, the feedforward quadrature shaft current is directly sent down as the pre-set compensation data and forcibly overwritten and loaded into the physical memory cache address space of the isolation register reserved in the core of the inverter drive controller motherboard. In the logic scan cycle of the dual closed-loop field-oriented decoupling control algorithm at the bottom layer of the inverter main control chip, the feedforward quadrature shaft current loaded in the isolation register is directly extracted and introduced into the inverter operation logic node as high-priority bypass constraint data. It is then combined with the feedback current reference output from the speed outer loop and subjected to digital parallel arithmetic superposition and summation in the inner high-speed logic adder. The resulting total current command directly bypasses the low-speed integrator and is imported into the high-frequency response execution comparison inner loop.

[0078] Finally, the total current command generated by the merging of the direct current inner loop drives the full-bridge hardware power switch module to perform voltage inverter chopper modulation to output high-frequency alternating current. This ensures that the pressure pulse wave caused by the group throttling in the wide-area water network actually crosses the pipeline distance and reaches the end face of the circulating water pump mechanically doing work at the same time. The stator of the drive motor synchronously establishes a compensating electromagnetic torque with the same amplitude and opposite direction as the external transient mechanical load torque to maintain mechanical force balance.

[0079] This invention also discloses a motor control system based on torque feedforward, including a processor and a memory. The memory stores computer program instructions, which, when executed by the processor, implement a motor control method based on torque feedforward according to the present invention.

[0080] The system also includes other components well known to those skilled in the art, such as communication buses and communication interfaces, the settings and functions of which are known in the art and will not be described in detail here.

Claims

1. A motor control method based on torque feedforward, characterized in that, include: Construct a spatiotemporal topology matrix for a wide-area network and capture spatially distributed digital service scheduling instruction data; The actual total span of the intelligent electronic control valves at each terminal is calculated based on the spatiotemporal topology matrix of the wide-area pipeline network. The intrinsic sound velocity of the fluid and the real-time macroscopic convection velocity of the fluid are obtained. A fluid acoustic-flow coupling transient delay model is constructed, and the arrival time window of the pressure pulse wave is analyzed to obtain the dynamic transient propagation delay. Based on the action timestamp and the target opening change, a single effective flow area function is constructed to characterize the change of the effective flow cross section of a single terminal intelligent electric control valve over time. The hydraulic contribution weight coefficient of each pipeline branch is calculated. Combined with the dynamic transient propagation delay, the single effective flow area functions are time-shifted and spatially weighted and summed to establish a spatiotemporal distributed delay model. The time-series equivalent network flow area characterizing the comprehensive equivalent flow cross section of the entire network is then reconstructed. The dynamic feedforward torque reference is obtained by deriving the pre-evolution equation using the time-equivalent network flow area and the drive motor feedback parameters, and the torque trajectory deviation integral is constructed based on the dynamic feedforward torque reference and the actual electromagnetic torque for system fault tolerance monitoring. The dynamic feedforward torque reference is converted into a feedforward quadrature-axis current and injected directly into the inner current loop as a high-priority bypass command to control the output compensation electromagnetic torque of the drive motor.

2. The motor control method based on torque feedforward according to claim 1, characterized in that, The spatially distributed digital service scheduling instruction data includes: action timestamp, initial absolute opening angle, target absolute opening angle, and target opening change.

3. The motor control method based on torque feedforward according to claim 1, characterized in that, The process of obtaining the dynamic transient propagation delay includes: calculating the sum of the fluid intrinsic sound velocity and the real-time fluid macroscopic convection velocity as the wave velocity; calculating the ratio of the actual total span of the pipeline network to the wave velocity; and obtaining the dynamic transient propagation delay generated by the terminal intelligent electronic control valve.

4. The motor control method based on torque feedforward according to claim 2, characterized in that, The construction of a single-unit effective flow area function, which characterizes the change of the effective flow cross-section of a single-terminal intelligent electronically controlled valve over time based on the action timestamp and the target opening change, includes: Obtain the mechanical angular velocity of the valve core of the micro DC motor inside the terminal intelligent electric control valve; calculate the absolute value of the target opening change, divide the absolute value by the mechanical angular velocity of the valve core, and obtain the full stroke execution time; A piecewise function for the real-time opening angle is constructed based on the initial absolute opening angle, the target absolute opening angle, the action timestamp, the full stroke execution time, and the valve core mechanical angular velocity. The inherent flow coefficient is obtained based on the factory technical parameter book of the terminal intelligent electric control valve, and a valve core section mapping function is constructed based on its inherent flow characteristic curve. The effective flow area function of the single unit is derived by using the inherent flow coefficient, the valve core section mapping function and the piecewise function of the real-time opening angle.

5. The motor control method based on torque feedforward according to claim 1, characterized in that, Calculate the hydraulic contribution weighting coefficient of each pipeline branch, and combine the dynamic transient propagation delay with the effective flow area function of each individual unit for time shifting and spatial weighted summation to establish a spatiotemporal distributed delay model. Reconstruct the time-series equivalent network flow area representing the overall equivalent flow cross-section of the entire network, including: The design volumetric flow rate is obtained by multiplying the cross-sectional area of ​​the pipe corresponding to the pipe branch in the spatiotemporal topology matrix of the wide area pipe network with the rated design flow velocity. The proportion of the volumetric flow rate of this design volumetric flow rate in the total heating flow of the whole network is calculated and set as the hydraulic contribution weighting coefficient. Using the hydraulic contribution weighting coefficient, a backward translation geometric mapping operation is performed on the effective flow area function of each individual cell on the time axis, with a time length equal to the dynamic transient propagation delay. At the current moment, a matrix space weighted summation operation is performed to obtain the time-series equivalent network flow area.

6. The motor control method based on torque feedforward according to claim 1, characterized in that, The formula for calculating the dynamic feedforward torque reference is: ； In the formula, This is the system clock time; For a moment Dynamic feedforward torque reference; It is the resistance constant; To improve overall conversion efficiency; For a moment The time-equivalent network circulation area; For target loop flow; For a moment The mechanical angular velocity of the drive motor.

7. The motor control method based on torque feedforward according to claim 4, characterized in that, The integral of the torque trajectory deviation includes: Obtain the shortest dynamic transient propagation delay included in the delay calculation results of all network pipeline branches. With the longest dynamic transient propagation delay Combined with the global maximum full-process execution time With action timestamps As the starting offset point, construct the deviation monitoring time integration observation window. ; Within the deviation monitoring time integration observation window, the absolute value of the difference between the real electromagnetic torque and the dynamic feedforward torque reference is accumulated over a time infinitesimal element to extract the torque trajectory deviation integral.

8. The motor control method based on torque feedforward according to claim 7, characterized in that, The system fault tolerance monitoring includes: Set the tolerance safety integral threshold; When the integral of the torque trajectory deviation exceeds the tolerance safety integral threshold, it is determined that the terminal intelligent electronic control valve of the current pipeline branch has mechanical jamming failure, interrupting the pre-evolution equation and cutting off the feedforward torque transmission link path, switching back to the constant torque steady-state control strategy based on pressure sensor feedback, and reporting the system equipment pipeline failure alarm message.

9. The motor control method based on torque feedforward according to claim 1, characterized in that, The dynamic feedforward torque reference is converted into a feedforward quadrature-axis current and injected directly into the inner current loop as a high-priority bypass command to control the output compensation electromagnetic torque of the drive motor, including: Extract the electromagnetic torque mapping transformation constant coefficients that are factory-fixed for the drive motor, divide the dynamic feedforward torque reference by the electromagnetic torque mapping transformation constant coefficients, and generate the feedforward quadrature axis current. In the logic scan cycle of the dual closed-loop magnetic field orientation decoupling control algorithm at the bottom layer of the frequency converter main control chip, the feedforward quadrature axis current is extracted and introduced into the frequency converter operation logic node. It is then combined with the feedback current reference output from the speed outer loop in the inner high-speed logic adder to perform a digital parallel arithmetic superposition and summation operation. The generated total current reference instruction is then passed through the low-speed integrator and introduced into the high-frequency response to execute the comparison inner loop. Using the total current reference command, the full-bridge hardware power switch module is driven to perform voltage inverter chopper modulation to output high-frequency alternating current. This controls the stator of the drive motor to synchronously establish a compensating electromagnetic torque with the same amplitude and opposite direction as the external transient mechanical load torque at the same time node when the pressure pulse wave arrives at the end face of the circulating water pump mechanically doing work.

10. A motor control system based on torque feedforward, characterized in that, include: A processor and a memory, the memory storing computer program instructions that, when executed by the processor, implement a motor control method based on torque feedforward according to any one of claims 1-9.

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