A ship rotating drum wind sail self-energy supply synergistic intelligent control method

Abstract

The present application relates to the technical field of ship wind boosting control, and discloses a ship rotating drum wind sail self-energy supply synergistic efficiency intelligent control method, which synchronously extracts ship body three-axis posture and motor electrical parameters, calculates rigid body alternating gyroscopic moment, filters and obtains equivalent dynamic disturbance torque, converts the equivalent dynamic disturbance torque, deducts the equivalent dynamic disturbance torque from the cross-axis current to obtain decoupling cross-axis current for evaluating net efficiency; when the absolute value of roll angular velocity exceeds the limit, the disturbance torque derivative is used to generate an opposite phase damping torque, and the transmission gap dead zone is used to limit the torque change rate; when there is no effective wind load and the roll continues, and the energy storage state of charge meets the condition, the energy storage drive motor is used to superimpose an opposite phase speed modulation component, and an equivalent roll damping is generated through posture coupling and phase compensation. The present application separates mechanical disturbance and aerodynamic load under alternating working conditions, relieves the rigid impact of the transmission chain, and reuses the rotating drum inertia to reduce roll, and takes into account energy efficiency evaluation, equipment protection and posture stability.

Description

Technical Field

[0001] This invention relates to the field of ship wind-powered propulsion control technology, specifically to an intelligent control method for synergistic efficiency enhancement of ship rotary sails and wind turbines. Background Technology

[0002] Rotary sails, as auxiliary propulsion devices for ships based on the Magnus effect, generate aerodynamic thrust by rotating an external cylindrical rotor driven by an electric motor, under the influence of ambient wind, thereby reducing the energy consumption and emissions of the ship's main engine. Existing rotary sail control systems typically obtain propulsion force by adjusting the speed or torque of the drive motor through a frequency converter based on external environmental data such as wind speed and direction. Under normal, stable sea conditions, this control method can maintain the basic operation of the system and output the expected auxiliary thrust.

[0003] Ships often face complex sea conditions with alternating winds and waves during actual navigation. Wave excitation causes multi-degree-of-freedom swaying of the hull. In this situation, the load on the sail support structure includes not only the aerodynamic loads generated by the wind field but also the mechanical disturbances caused by the hull swaying. Existing control systems struggle to decouple these two loads with different physical properties from the mixed motor operating parameters, leading to biased assessments of the actual aerodynamic propulsion benefits and failing to provide accurate closed-loop data for system performance optimization. Furthermore, under alternating operating conditions caused by severe sea conditions, the motor frequently switches between positive and negative torque. Existing control strategies do not limit transmission backlash when torque crosses zero, making the transmission chain highly susceptible to reverse mechanical rigidity impacts. This increases the alternating stress on the tower bottom support structure and the bottom bearings, lacking an effective dynamic mechanical protection mechanism.

[0004] When faced with sea conditions where wind loads approach zero but are accompanied by persistent long-wave swells, existing sail systems typically shut down or operate at low speeds. The sail turret itself possesses a large mass and moment of inertia, but under current control logic, it functions merely as a passive load-bearing structure, failing to utilize this physical property to actively intervene in the ship's attitude. The system cannot utilize this situation to schedule the energy storage drive motor to generate variable-speed motion, nor can it generate alternating gyroscopic torque to create roll damping compensation, thus failing to improve ship stability without adding additional dedicated anti-roll equipment. Therefore, this invention provides a self-powered, synergistic, and intelligent control method for ship turret sails to address the shortcomings of existing technologies. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a self-powered, synergistic, and intelligent control method for ship rotary sails. This method solves the problems of existing rotary sail control systems, such as distorted evaluation of operating parameters due to the coupling of mechanical disturbances and aerodynamic loads in complex sea conditions, lack of dynamic mechanical protection of the transmission chain under alternating operating conditions, and inability to utilize the sail's rotational inertia for active ship roll reduction control.

[0006] To achieve the above objectives, the present invention provides the following technical solution: The first aspect of this invention provides a smart control method for synergistic efficiency enhancement of self-powered ship rotary sails, comprising: The three-axis attitude angular velocities, including roll, pitch, and yaw angular velocities, as well as the rotor mechanical angular velocity, rotor position angle, stator direct-axis current, original stator quadrature-axis current, stator direct-axis voltage, and stator quadrature-axis voltage are extracted synchronously according to the sampling period. The rigid body alternating gyroscope torque is calculated using the three-axis attitude angular velocity and the rotor mechanical angular velocity. The attitude coupling is performed in combination with the installation deflection angle. The equivalent dynamic disturbance torque is obtained by filtering through the elastic structure transfer function. This torque is then converted and subtracted from the original stator quadrature axis current to obtain the decoupled quadrature axis current. The equivalent saved shaft power is calculated by using the decoupled quadrature shaft current and rotor mechanical angular velocity, and the difference between the calculated power and the real-time active power is used to generate a transient net efficiency gain index, which serves as the basis for speed adjustment or mode switching. When the absolute value of the roll angular velocity exceeds the upper limit judgment threshold, the derivative of the equivalent dynamic disturbance torque is used to generate the target damping torque command, which is combined with the aerodynamic maintaining torque base value to form the target electromagnetic torque command. The segmented torque change rate limit is executed in the dead interval of the transmission clearance, and the final command is generated and issued for execution. When the effective value of the decoupled quadrature current is lower than the preset wind load lower limit, the integral of the absolute value of the roll angular velocity is higher than the roll excitation threshold but not higher than the upper limit judgment threshold, and the state of charge of the energy storage element is higher than the discharge protection lower limit threshold within the set time window, the active gyroscope roll reduction mode is switched on. The energy storage power drives the motor to superimpose the speed modulation component opposite to the roll angular acceleration on the base low speed. The generated alternating gyroscope torque is transmitted through support, attitude coupling and phase compensation to form an equivalent roll damping compensation torque.

[0007] Furthermore, the step of synchronously extracting the three-axis attitude angular velocities (including roll, pitch, and yaw angular velocities), rotor mechanical angular velocity, rotor position angle, stator direct-axis current, original stator quadrature-axis current, stator direct-axis voltage, and stator quadrature-axis voltage according to the sampling period specifically includes: using an industrial Ethernet bus protocol for distributed clock synchronization; broadcasting synchronization messages at fixed periods to trigger hardware timers to generate interrupts; latching the three-axis attitude angular velocities, rotor mechanical angular velocity, rotor position angle, stator direct-axis current, original stator quadrature-axis current, stator direct-axis voltage, and stator quadrature-axis voltage; and configuring the same period sequence number for the data obtained from the same synchronization message for matching and alignment. Using this method, by matching the period sequence number with the underlying hardware interrupt, the phase error caused by sensor sampling frequency differences and communication link transmission can be eliminated, allowing the ship's spatial attitude data and the motor's electrical state to participate in dynamic calculations within the same time domain.

[0008] Furthermore, the calculation of the rigid body alternating gyro torque using the three-axis attitude angular velocities and the rotor mechanical angular velocities specifically includes: constructing a spatial attitude angular velocity vector from the extracted three-axis attitude angular velocities, which includes the roll angular velocity around the X-axis of the ship's following coordinate system, the pitch angular velocity around the Y-axis, and the yaw angular velocity around the Z-axis; constructing a rotary sail rotation angular velocity vector based on the extracted rotor mechanical angular velocities, wherein the rotary sail rotation angular velocity vector has an angular velocity component only in the Z-axis direction of the ship's following coordinate system; performing a spatial cross product calculation between the spatial attitude angular velocity vector and the rotary sail rotation angular velocity vector, and multiplying by a pre-calibrated rotational inertia matrix of the rotary sail system to obtain the spatial alternating gyro torque vector; and extracting the scalar projection component of the spatial alternating gyro torque vector on the radial plane of the drive motor spindle as the theoretical radial disturbance torque. The process of extracting the theoretical radial disturbance torque described above is essentially mapping and quantifying the spatial coupling effect generated by the multi-degree-of-freedom hull swaying and rotor rotation into a radial load excitation component that directly acts on the bottom drive bearing.

[0009] Furthermore, the process of obtaining the equivalent dynamic disturbance torque through filtering with the elastic structure transfer function specifically includes: discretizing the pre-defined second-order elastic structure transfer function in the Laplace domain into a Z-domain pulse transfer function using the bilinear transform method, and converting it into a time-domain difference equation; substituting the theoretical radial disturbance torque values ​​at the current and historical moments into the time-domain difference equation for iterative calculation to obtain the equivalent dynamic disturbance torque. The introduction of the pre-defined second-order elastic structure transfer function for iterative calculation aims to compensate for the phase lag and local resonance amplification of torque transmission caused by deformation of the tower and support structure, thereby deriving the actual mechanical dynamic disturbance values ​​transmitted to the motor shaft end.

[0010] Furthermore, the step of converting the current to a stator electromagnetic disturbance current component and subtracting it from the original stator quadrature-axis current to obtain the decoupled quadrature-axis current specifically includes: multiplying the equivalent dynamic disturbance torque by a pre-calibrated bearing friction torque coupling coefficient, dividing by the product of the number of pole pairs of the drive motor, the rotor flux linkage, and the constant 1.5, to obtain the stator electromagnetic disturbance current component; and executing a subtraction decoupling equation in the vector control loop to subtract the stator electromagnetic disturbance current component from the original stator quadrature-axis current to obtain the decoupled quadrature-axis current. By executing the subtraction decoupling equation, the system can separate the mechanical motion disturbance term from the quadrature-axis current, which includes external wind aerodynamic loads and ship sway mechanical disturbances, thus completing the feedforward decoupling of the aerodynamic load parameters.

[0011] Furthermore, the step of calculating the equivalent shaft-saving power using the decoupled quadrature-axis current and the rotor mechanical angular velocity, simultaneously calculating the real-time interactive active power, and obtaining the difference between the two to generate the transient net efficiency gain index specifically includes: substituting the decoupled quadrature-axis current and the rotor mechanical angular velocity into the function mapping relationship obtained by joint calibration through wind tunnel test data and ship hydrodynamic data to calculate the equivalent shaft-saving power; calculating the active power using the stator direct-axis voltage, the stator quadrature-axis voltage, the stator direct-axis current, and the original stator quadrature-axis current based on the instantaneous power relationship in the synchronous rotating coordinate system; obtaining the algebraic difference between the equivalent shaft-saving power and the active power, and performing a sliding window averaging filter on the algebraic difference to generate the transient net efficiency gain index. In the above calculations, the transient net energy gain index refers to the algebraic difference between the effective aerodynamic thrust generated by the rotary sail (converted to equivalent shaft power saving, i.e., input contribution) and the actual active power consumed or fed back by the system (i.e., output loss), and after being processed by a sliding window filter, it is used to dynamically characterize the quantitative boundary index of the system's net energy efficiency benefit to the ship at the current moment. The propulsion benefit is represented by the decoupled cross-axis current after removing mechanical disturbances, and the active power consumed by the system to maintain rotation is deducted from this value. The resulting value can serve as a quantitative control basis reflecting the system's net energy benefit.

[0012] Furthermore, the step of generating the target electromagnetic damping torque command using the derivative of the equivalent dynamic disturbance torque specifically includes: performing discrete difference analysis on the equivalent dynamic disturbance torque to obtain the time rate of change of the equivalent dynamic disturbance torque; performing a first-order low-pass digital filter on the time rate of change of the equivalent dynamic disturbance torque, and multiplying the filtered result by the negative damping gain coefficient to generate the target electromagnetic damping torque command; and superimposing the target electromagnetic damping torque command with the aerodynamic holding torque base value of the rotary sail to form the target electromagnetic torque command. Generating the target electromagnetic damping torque command based on the rate of change of the equivalent dynamic disturbance torque can inject reverse electromagnetic damping into the system in response to mechanical disturbance trends, suppress stress alternation in the underlying transmission components, and provide mechanical protection for the tower bottom support structure during regenerative power generation.

[0013] Furthermore, the step of limiting the segmented nonlinear torque change rate based on the transmission gap dead zone where the current target electromagnetic torque command is located specifically includes: real-time monitoring of the target electromagnetic torque command; setting the transmission gap dead zone on both sides of zero torque according to a preset transmission gap dead zone threshold; when the target electromagnetic torque command falls into the transmission gap dead zone, using a restricted torque change rate threshold to limit the torque change rate and reduce the response bandwidth of the current control loop; when the target electromagnetic torque command leaves the transmission gap dead zone, using a conventional physical limit change rate threshold to limit the torque change rate; the restricted torque change rate threshold is less than the conventional physical limit change rate threshold. Setting the transmission gap dead zone on both sides of zero torque and performing segmented nonlinear torque change rate limiting can reduce the torque step amplitude in the zero-crossing interval when the control system outputs alternating braking torque, avoiding mechanical reverse rigid impact caused by backlash or torsional clearance in the transmission chain.

[0014] Furthermore, the determination condition when the decoupled cross-axis current approaches zero and the integral value of the absolute value of the roll velocity is higher than the preset roll excitation threshold is as follows: Calculate the effective value of the decoupled cross-axis current within a set time window, and calculate the integral value of the absolute value of the roll velocity within the same time window; when the effective value of the decoupled cross-axis current is continuously lower than the preset lower wind load threshold, and the integral value of the absolute value of the roll velocity is higher than the preset roll excitation threshold, it is determined that the decoupled cross-axis current approaches zero and the integral value of the absolute value of the roll velocity is higher than the preset roll excitation threshold; at this time, if the absolute value of the roll velocity does not exceed the upper limit determination threshold and the state of charge of the energy storage element is higher than the lower limit threshold of the discharge protection, then the active gyroscope roll reduction mode is entered. This multi-dimensional logic determination condition combines decoupled airflow load, attitude time integral, and energy storage state, eliminating interference from short-term gusts or single waves, and is used to identify specific working conditions where there is no effective aerodynamic propulsion wind but is accompanied by continuous long-wave surges.

[0015] Furthermore, the method of using energy storage elements to drive the motor in a low-speed rotational state, superimposing a speed modulation component opposite to the roll acceleration, specifically includes: scheduling the energy storage elements to release electrical energy to maintain the low-speed rotational state at the basic low-speed angular velocity; performing discrete differential and low-pass filtering on the roll angular velocity to obtain the roll acceleration, multiplying the roll acceleration by a negative roll reduction gain coefficient to generate the speed modulation component; superimposing the speed modulation component on the basic low-speed angular velocity to form a comprehensive speed command; and inputting the comprehensive speed command into the speed control loop after limiting it to between the minimum positive maintaining speed and the maximum mechanically permissible speed using a saturation limiter. The system achieves self-powering in this way; that is, when there is no effective wind field and active roll reduction conditions are available, the system does not require power from the ship's microgrid backbone, but instead independently completes the energy supply process for driving the motor's low-speed rotation and alternating speed modulation by scheduling energy storage elements directly connected to the inverter's DC bus to release electrical energy. In active gyro roll reduction mode, the rotational inertia of the sail turret itself is utilized to generate alternating gyro torque by adjusting the rotor speed. This torque is transmitted to the hull through the support structure, forming anti-roll damping and improving the ship's roll stability. The equivalent roll damping compensation torque formed here is the original alternating rigid body gyro torque caused by the alternating rotation of the motor. After overcoming the elastic deformation transmission loss of the support structure, completing attitude coupling through angular installation or spatial decomposition, and completing phase compensation by pre-correcting time lag through algorithms, it ultimately acts as a macroscopic damping torque in the direction of the ship's roll motion, producing a smoothing effect on the sway.

[0016] A second aspect of the present invention provides a ship rotary sail self-powered synergistic efficiency enhancement intelligent control system, comprising: An inertial measurement unit (IMU) is rigidly fixed to the ship's reference spatial position and is used to output the ship's three-axis attitude angular velocity data in real time. The four-quadrant frequency converter has an energy storage element connected to its DC bus circuit and its output terminal connected to the stator winding of the drive motor, which is used to drive the motor to work in electric mode or regenerative braking mode; the four-quadrant frequency converter has an integrated sampling circuit, which is used to collect and output the stator direct-axis voltage, stator quadrature-axis voltage, stator direct-axis current and original stator quadrature-axis current in real time. The drive motor has its rotor shaft mechanically coupled to the bottom support bearing of the rotating sail; the end of the drive motor is equipped with a position sensor for outputting the rotor's mechanical angular velocity and rotor position angle. The main control unit establishes a distributed clock synchronization communication connection with the inertial measurement unit, the four-quadrant frequency converter, and the position sensor via an industrial Ethernet bus. The main control unit is equipped with a hardware timer, which is used to broadcast synchronization messages at fixed intervals and latch and align the data of each sensor node when an interrupt is triggered.

[0017] The main control unit is equipped with decoupling calculation logic, which is used to calculate and extract the equivalent dynamic disturbance torque by using the synchronously acquired three-axis attitude angular velocity and rotor mechanical angular velocity, and subtract its converted component from the original stator quadrature-axis current in the vector control loop to obtain the decoupling quadrature-axis current; the decoupling calculation logic synchronously combines the active power and equivalent saved shaft power of the motor operation interaction to output the transient net efficiency gain index, which serves as the basis for target speed adjustment or mode switching.

[0018] The main control unit is equipped with variable frequency drive and protection logic, which evaluates the operating status in real time based on the roll rate: when the absolute value of the roll rate exceeds the upper limit judgment threshold, the anti-phase electromagnetic damping torque is calculated based on the derivative of the equivalent dynamic disturbance torque, and the torque change rate limit threshold is lowered when the target electromagnetic torque command passes through the dead interval of the transmission gap; when the decoupled quadrature current approaches zero within the set time window, the integral value of the absolute value of the roll rate is higher than the preset roll excitation threshold and the absolute value of the roll rate does not exceed the upper limit judgment threshold, and the state of charge of the energy storage element is higher than the lower limit threshold of the discharge protection, the energy storage element is scheduled to supply power to the drive motor, generating a speed command superimposed with a differential anti-phase modulation component of the roll rate, driving the rotary sail to output an alternating rigid body gyro torque for ship roll reduction compensation. Based on the above logic, the main control unit calculates net efficiency and mechanical load through internal algorithms according to the attitude and electrification data synchronously input from multiple sources. It can autonomously determine the system operating condition without human intervention and seamlessly switch between modes such as aerodynamic thrust optimization, regenerative power generation and mechanical protection, and active gyroscope roll reduction, thereby realizing the automated intelligent control of the system.

[0019] This invention provides an intelligent control method for synergistic efficiency enhancement of ship rotary sail self-powered systems. It has the following beneficial effects: 1. This invention calculates the rigid body alternating gyro torque by extracting the hull attitude angular velocity and rotor mechanical angular velocity, and obtains the equivalent dynamic disturbance torque by combining it with elastic structure transfer function filtering. This torque is then converted into an electromagnetic disturbance current component and subtracted from the original stator quadrature-axis current. This mechanism separates the mechanical disturbance caused by hull swaying from mixed operating data including wave excitation and wind loads, obtaining a decoupled quadrature-axis current that reflects the actual aerodynamic propulsion benefits. This provides an objective data basis for evaluating the transient net performance gain and performing closed-loop control.

[0020] 2. This invention sets a threshold condition based on the roll rate, generates an anti-phase electromagnetic damping torque command using the rate of change of the equivalent dynamic disturbance torque, and executes a restricted torque change rate limiting when the electromagnetic torque command is in the transmission backlash dead zone near zero torque. When facing severe sea conditions, this control strategy can inject reverse damping into the system to suppress stress alternation in the underlying transmission components, while mitigating the step amplitude when the torque crosses zero, avoiding mechanical reverse rigid impact caused by gear backlash or torsional clearance, thus achieving dynamic protection for the tower support structure and transmission chain.

[0021] 3. In specific sea conditions where the decoupled quadrature-axis current approaches zero and the roll rate is continuous, this invention switches to an active gyro-based roll reduction mode. This mode involves scheduling the energy storage element to drive the motor, which rotates at a very low speed and superimposes a velocity modulation component that is inversely phase to the differential of the roll rate. This process reuses the rotational inertia of the large rigid structure of the sail rotor, causing it to generate alternating physical gyroscopic torque according to control commands. This torque is transmitted to the hull through the underlying support structure, forming roll damping compensation. This improves the ship's attitude stability without requiring additional dedicated roll reduction equipment. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the system hardware topology of the present invention; Figure 2 This is a schematic diagram of the control method of the present invention. Figure 3 This is a timing diagram of the real-time synchronous extraction steps of multi-source physical state data in this invention; Figure 4 This is a block diagram illustrating the principle of the gyroscope torque decoupling calculation steps based on elastic structure transmission filtering according to the present invention. Figure 5 This is a principle block diagram of the real-time construction step of the transient net performance gain index of the present invention; Figure 6 This is the control logic diagram for the transient four-quadrant switching scheduling and zero-crossing torque constraint steps of the present invention; Figure 7 This is a logic flowchart of the active gyroscope anti-roll control steps under calm and high-wave conditions according to the present invention. Figure 8 This is a logic diagram of the evolution of multiple sea state operating conditions and the switching of control modes in this invention; Figure 9 This is a comparative verification curve of the conventional control and the synergistic intelligent control of the present invention on key physical parameters. Detailed Implementation

[0023] The technical solutions in 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 embodiments of the present invention, and not all embodiments. 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.

[0024] See attached document Figure 1 This invention provides a ship rotary sail self-powered synergistic efficiency enhancement intelligent control system, the system includes: a main control unit, an inertial measurement unit, a four-quadrant frequency converter and a drive motor.

[0025] As the core control node of the system, the main control unit establishes real-time data communication connections with the inertial measurement unit and the four-quadrant frequency converter through a deterministic industrial Ethernet bus.

[0026] The inertial measurement unit is rigidly fixed to the ship's reference spatial position. It is responsible for sensing the ship's multi-degree-of-freedom motion state under wave excitation in real time and outputting three-axis attitude angular velocity data, including roll, pitch and yaw, to the bus network at high frequency.

[0027] The input of the four-quadrant frequency converter is connected in parallel to the AC bus of the ship's microgrid, and the DC bus circuit is connected to an energy storage element. The electrical energy stored in the energy storage element enables the four-quadrant frequency converter to independently output energy to the drive motor in calm and high-swell sea conditions, maintaining the rotor shaft in a low-speed rotation state powered by the energy storage. The output of the four-quadrant frequency converter is connected to the stator winding of the drive motor.

[0028] The rotor shaft of the drive motor is mechanically coupled to the bottom support bearing of the rotating sail. The four-quadrant frequency converter receives vector control commands from the main control unit, drives the drive motor to operate in electric mode or regenerative braking mode, and controls the bidirectional power flow between the microgrid and the drive motor.

[0029] See attached document Figure 2 This invention provides a smart control method for synergistic efficiency enhancement of self-powered ship rotary sails, comprising the following steps: S1, based on the set sampling period, synchronously extracts the three-axis attitude angular velocities output by the inertial measurement unit, including roll angular velocity, pitch angular velocity and yaw angular velocity, as well as the rotor mechanical angular velocity, rotor position angle, stator direct axis current, original stator quadrature axis current, stator direct axis voltage and stator quadrature axis voltage at the bottom layer of the four-quadrant frequency converter; S2, calculate the rigid body alternating gyroscope torque using the three-axis attitude angular velocity and the rotor mechanical angular velocity, filter the rigid body alternating gyroscope torque using the elastic structure transfer function to obtain the equivalent dynamic disturbance torque, convert the equivalent dynamic disturbance torque into the stator electromagnetic disturbance current component, and subtract the stator electromagnetic disturbance current component from the original stator quadrature axis current to obtain the decoupled quadrature axis current; S3, calculate the equivalent shaft power saving by mapping the decoupled quadrature shaft current and rotor mechanical angular velocity, simultaneously calculate the active power of the real-time interaction on the four-quadrant frequency converter side, and obtain the algebraic difference value obtained by subtracting the active power from the equivalent shaft power saving to generate the transient net efficiency gain index. S4. The system operating status is determined based on the relationship between the absolute value of the roll angular velocity and the upper limit judgment threshold. When the absolute value of the roll angular velocity exceeds the upper limit judgment threshold, the target electromagnetic damping torque command is generated by using the real-time derivative of the equivalent dynamic disturbance torque. The segmented nonlinear torque change rate limiting equation is executed according to the transmission gap dead interval where the target electromagnetic torque command is located, and the final electromagnetic torque command is generated and sent to the four-quadrant frequency converter for execution. S5. When the effective value of the decoupled quadrature axis current is determined to be continuously lower than the preset wind load lower limit threshold within a set time window, and the integral value of the absolute value of the roll angular velocity is higher than the preset roll excitation threshold within the same set time window, and the state of charge of the energy storage element is higher than the discharge protection lower limit threshold, the active gyro roll reduction mode is switched to. The energy storage element drives the four-quadrant frequency converter to issue an alternating quadrature axis current command, which controls the drive motor to superimpose a speed modulation component that is opposite to the differential of the roll angular velocity on the basic low-speed angular velocity. The generated alternating rigid body gyro torque is transmitted through the support structure, attitude coupling and phase compensation to form an equivalent roll damping compensation torque, which is used as the roll damping compensation torque of the ship body to suppress the ship's roll motion.

[0030] The following will provide a detailed explanation of the specific technical implementation details of each step in this invention, in conjunction with the corresponding formulas and models.

[0031] See attached document Figure 3 To ensure that the ship's attitude data and the motor's electrical operation data participate in the dynamics calculation within the same control cycle, step S1 can be implemented as follows: S11, the main control unit synchronously extracts basic operating data such as hull attitude status, motor rotor status, and motor electrical status according to the set sampling period. The sampling period can be determined according to the execution period of the inverter current control loop, and is usually on the order of hundreds of microseconds to milliseconds to cover the dynamic changes in electrical status.

[0032] The main control unit uses the industrial Ethernet bus protocol for distributed clock synchronization to reduce phase errors caused by differences in sampling frequencies of different sensor hardware and transmission time in the communication link. In practice, the main control unit broadcasts synchronization messages at fixed intervals; after receiving the synchronization messages, the inertial measurement unit and the four-quadrant frequency converter generate interrupts through their respective internal hardware timers, triggering the latching of sensor data and analog-to-digital conversion data.

[0033] To facilitate subsequent data alignment, the main control unit can also configure the same cycle number or timestamp for data triggered by the same synchronization message, and perform matching according to the cycle number or timestamp after receiving data. The hull attitude state and the motor electrical operation state after synchronization latching and matching are regarded as data from the same sampling moment, and are used for subsequent gyro torque calculation, disturbance torque conversion, and current decoupling calculation.

[0034] The frequency of a ship's rolling motion in waves is usually lower than the motor's rotational frequency, but the attitude angular velocity and rotor angular velocity are involved in the same dynamic cross product calculation. If there is a significant time shift between the two types of data, the calculated disturbance torque will have a phase deviation. Therefore, using synchronous message triggering and cycle number matching helps to reduce phase errors in subsequent dynamic calculations.

[0035] S12, the inertial measurement unit (IMU) transmits the ship's real-time attitude and angular velocity data to the main control unit. The IMU establishes a hull-following coordinate system at the ship's reference position, defining the X-axis along the ship's bow and stern longitudinal centers, the Y-axis along the ship's port and starboard baselines, and the Z-axis perpendicular to the deck plane and upwards. The IMU outputs the angular velocity of rotation around these three axes.

[0036] The main control unit constructs the received three-axis angular velocity data into a spatial attitude angular velocity vector, the mathematical expression of which is: ; In the formula, for The ship's three-axis attitude angular velocity vector at time t. The angular velocity of the roll about the X-axis. The pitch angular velocity about the Y-axis, ω represents the initial angular velocity about the Z-axis.

[0037] S13, within the same data latching cycle, the four-quadrant frequency converter uploads the real-time operating physical quantities of the drive motor to the main control unit. Internally, the four-quadrant frequency converter uses a field-oriented control algorithm to convert the stator three-phase AC physical quantities to a synchronous rotating coordinate system. The coordinate transformation and synchronous rotating coordinate system construction in field-oriented control can be implemented using conventional motor control methods.

[0038] The motor operating data extracted by the main control unit includes the rotor mechanical angular velocity of the drive motor. Rotor position angle And the stator direct-axis current mapped to the synchronous rotating coordinate system. Original stator quadrature-axis current Stator direct-axis voltage and stator cross-axis voltage The rotor mechanical angular velocity and rotor position angle can be obtained by a position sensor located at the motor shaft end, or by a sensorless observation algorithm; voltage and current data are obtained by sampling from the voltage and current detection circuit inside the four-quadrant frequency converter.

[0039] Since the main shaft of the rotary sail is mechanically directly connected to the rotor of the drive motor, the main control unit constructs the rotary sail's rotational angular velocity vector based on the collected rotor mechanical angular velocity: ; In the formula, for The angular velocity vector of the rotor sail at any given time. The rotor sail is installed perpendicular to the ship's deck. In embodiments where no installation offset is set, this vector has an angular velocity component only in the Z-axis direction of the ship's following coordinate system, and is used for subsequent spatial dynamics calculations.

[0040] See attached document Figure 4 To separate the mechanical disturbance component caused by the ship's attitude motion from the motor's quadrature-axis current, step S2 can be implemented as follows: S21, the main control unit uses the synchronously acquired three-axis attitude angular velocity vector of the ship and the rotation angular velocity vector of the rotary sail to calculate the rigid body alternating gyro torque.

[0041] The rotary sail has a large moment of inertia. As the hull's attitude angular velocity changes, the rotor's spin angular momentum couples with the hull's attitude angular velocity, generating an alternating gyroscopic torque in a direction orthogonal to the spin axis and the attitude angular velocity direction. The main control unit constructs a spatial cross product calculation formula based on rigid body dynamics relationships: ; In the formula, for The theoretical spatial alternating gyroscope torque vector at any given moment. This is the moment of inertia matrix of the rotary sail system. This matrix can be pre-measured and calibrated through three-dimensional model analysis of the rotary sail or factory installation test. This is the vector cross product operator. The vector cross product can be calculated using conventional rigid body dynamics methods.

[0042] Main control unit extraction The scalar projection component on the radial plane of the drive motor spindle is taken as the theoretical radial disturbance torque. The scalar projection component is determined based on the main load-bearing direction of the bottom support bearing of the rotary sail and the installation reference direction of the drive motor, and retains the positive and negative signs corresponding to the direction of radial load change of the bearing, so that subsequent current decoupling calculations can distinguish the loading and unloading directions of the disturbance torque.

[0043] In the embodiment where the bottom support structure of the rotary sail adopts a preset installation angle, the main control unit first corrects the coordinate direction of the rotor's rotation axis according to the installation angle, and then performs spatial cross product calculation and radial plane projection; in the embodiment where no installation angle is set, the rotor's rotation axis participates in the calculation according to the Z-axis direction of the hull's follow-up coordinate system.

[0044] S22, the main control unit uses a pre-calibrated elastic structure transfer function to filter the theoretical radial disturbance torque. The rotating sail tower and its bottom support structure have elastic deformation characteristics. When the theoretical radial disturbance torque is transmitted from the upper part of the tower to the drive motor shaft, it will produce phase lag, amplitude attenuation, or local resonance amplification. To estimate the disturbance torque transmitted to the drive motor shaft, the main control unit establishes a second-order structure transfer function in the control program: ; In the formula, Let be the transfer function of a second-order elastic structure in the Laplace domain. For the Laplace operator, The natural frequency of the rotary sail tower system, The structural damping ratio is the natural frequency. The natural frequency and structural damping ratio can be obtained through impact tests or frequency sweep tests under static conditions and written into the memory of the main control unit.

[0045] To perform structural transfer filtering in the discrete control program, the master control unit uses the bilinear transform method to discretize the Laplace domain transfer function into a Z-domain impulse transfer function, and then converts it into a time-domain difference equation. Within each sampling period, the master control unit substitutes the theoretical radial disturbance torque values ​​from the current and historical times into this time-domain difference equation for iterative calculation to obtain the equivalent dynamic disturbance torque. This equivalent dynamic disturbance torque is used to characterize the mechanical disturbance component transmitted to the drive motor shaft.

[0046] S23, the main control unit performs mechanical-electrical feedforward current decoupling calculation. The original stator quadrature-axis current collected by the four-quadrant frequency converter includes the effective load component formed by the aerodynamic action of the external wind field, as well as the mechanical disturbance component caused by the ship's rolling motion. The equivalent dynamic disturbance torque generated by the ship's rolling motion acts on the bottom support bearing of the swivel sail, causing the radial load of the bearing to change alternately. This change in radial load manifests as an additional equivalent resistance torque in the rotation direction of the drive motor's main shaft through bearing friction, sealing resistance, and the spindle off-center load effect, forming an observable disturbance component in the quadrature-axis current.

[0047] To extract the current signal that primarily characterizes the aerodynamic load of the sail, the main control unit converts the equivalent dynamic disturbance torque in the mechanical domain into a stator electromagnetic disturbance current component, and performs a subtraction decoupling equation in the inverter's vector control loop: ; In the formula, This variable forms the data basis for subsequent net performance evaluation, as it is used to eliminate the decoupled quadrature-axis current after mechanical disturbances are removed. The original stator quadrature-axis current sampled in real time by the four-quadrant frequency converter; The bearing friction torque coupling coefficient is a pre-calibrated value used to characterize the physical transmission ratio of radial torque to axial resistance torque of the motor spindle. It is usually set within an empirical range of 0.01 to 0.05, taking into account the mechanical characteristics of the bearing structure and the support structure.

[0048] During specific calibration, the drive motor can be kept rotating at a constant low speed, and a radial load or radial bending moment of known magnitude can be applied to the bottom support structure of the rotating sail through a loading device. The increment of the quadrature-axis current required to maintain a constant speed is recorded simultaneously, and then the result is obtained by fitting the correspondence between the change in radial load and the increment of quadrature-axis current. .

[0049] In this embodiment, the drive motor is a surface-mounted permanent magnet synchronous motor, or a direct-axis current control strategy that makes the influence of reluctance torque negligible. The denominator of the conversion formula is constructed based on the electromagnetic torque relationship of the permanent magnet synchronous motor, wherein... The pole pair number is a nameplate parameter for the drive motor. These are the rotor flux linkage nameplate parameters for the drive motor. When the drive motor adopts an embedded permanent magnet synchronous motor or other motor structure with significant reluctance torque components, the main control unit can use a pre-calibrated equivalent torque coefficient to replace the above electromagnetic torque conversion relationship in order to maintain the correspondence between the mechanical disturbance torque and the quadrature axis current disturbance component.

[0050] After the above processing, the main control unit obtains the decoupled quadrature-axis current for subsequent net performance evaluation, thereby reducing the impact of ship attitude motion on aerodynamic load current estimation.

[0051] See attached document Figure 5 To obtain the net energy gain evaluation during the operation of the rotary sail, step S3 can be implemented as follows: In S31, the main control unit uses the decoupled quadrature-axis current and rotor mechanical angular velocity to calculate the equivalent shaft power saving corresponding to the Magnus effect. After eliminating the interference caused by mechanical swaying motion, the decoupled quadrature-axis current can characterize the aerodynamic load component of the rotary sail within the conventional aerodynamic thrust optimization mode or steady-state constant speed operation window. When the system is in the four-quadrant regenerative power generation and mechanical protection mode or the active gyro anti-roll mode, the main control unit suspends the aerodynamic load update based on the decoupled quadrature-axis current, or performs aerodynamic load estimation after deducting the known active control command current component.

[0052] The decoupled quadrature-axis current of the drive motor has a corresponding relationship with the electromagnetic torque. When the rotor sail rotates stably, this electromagnetic torque is mainly used to overcome the aerodynamic frictional resistance torque on the rotor surface. Within a certain speed ratio range, there is a calibrable hydrodynamic correlation between this aerodynamic frictional resistance torque and the lateral lift generated by the rotor and the propulsion component in the ship's forward direction. Based on this correlation, the main control unit pre-stores the function mapping relationship obtained by joint calibration of wind tunnel test data and ship hydrodynamic data.

[0053] In the basic implementation, the main control unit substitutes the decoupled quadrature-axis current and rotor mechanical angular velocity into the function mapping relationship to calculate the equivalent shaft power saving corresponding to the current Magnus effect thrust replacing the ship's main engine propulsion. In a preferred implementation, the main control unit can also introduce at least one navigation environment state variable from ship speed, apparent wind speed, or apparent wind direction, and correct the calibration parameters in the function mapping relationship by looking up tables, interpolation, or parameter correction methods to reduce the deviation generated when relying solely on the motor load current for aerodynamic benefit estimation.

[0054] The specific calculation equation is expressed as follows: ; In the formula, for The equivalent shaft power saving calculated at each moment; The comprehensive propulsion efficiency coefficient is used to characterize the conversion ratio of the aerodynamics generated by the rotary sail into the actual propulsion power of the ship. Its specific value is determined by the open water efficiency of the propeller and the wake fraction of the hull of the target ship. The parameters are identified and determined during the sea trial phase based on the specific ship type and the reference speed of the target ship. This refers to the rotor's mechanical angular velocity; To decouple the quadrature-axis current; and These are the first and second order fitting constants for the aerodynamic thrust characteristic curve, respectively. These constants were obtained by collecting wind tunnel test data from a scaled-down model of a rotary sail and using the least squares method to perform polynomial fitting on the aerodynamic drag torque and lift coefficient under different wind speed ratios. They are used to characterize the nonlinear conversion relationship between aerodynamic load and propulsion power under different speeds and wind conditions.

[0055] As a specific example of the equivalent shaft power saving calibration mapping relationship, for a rotary sail bulk carrier with a height of 30 meters and a diameter of 5 meters, under the calibration conditions of an apparent wind speed of 10 m / s and a wind direction angle of 90 degrees, the above fitting constants... and The values ​​can be determined to be 0.85 and -0.02 by combining wind tunnel test data and the open-water curve of the actual ship propeller. Based on this calibration relationship, the main control unit can directly map the equivalent shaft power saved by the current aerodynamic thrust by collecting the current decoupled quadrature-axis current in real time, providing a quantitative basis for net performance evaluation.

[0056] Through the above calculations, the main control unit obtains energy assessment data for subsequent speed adjustment control.

[0057] S32, while calculating the equivalent shaft power saving, the main control unit also calculates the active power exchanged between the four-quadrant inverter and the ship's microgrid. When the drive motor rotates the swivel sail, the four-quadrant inverter can absorb electrical energy from the ship's microgrid to maintain its speed, and can also feed electrical energy back to the ship's microgrid when regenerative braking conditions are met. Based on the instantaneous power relationship in the synchronous rotating coordinate system, the main control unit calculates the active power using the stator direct-axis voltage, stator quadrature-axis voltage, stator direct-axis current, and the original stator quadrature-axis current. ; In the formula, for The active power exchanged by the system at any time: a positive result indicates that electrical energy is absorbed from the ship's microgrid, and a negative result indicates that electrical energy is fed back to the ship's microgrid. and These are the stator direct-axis voltage and the stator quadrature-axis voltage, respectively. This refers to the stator direct-axis current. This is the original stator quadrature-axis current.

[0058] The active power calculation uses the original stator quadrature-axis current. Instead of using decoupling quadrature current The reason is that the actual energy exchange between the frequency converter and the ship's microgrid includes energy changes caused by aerodynamic loads, mechanical disturbances, and active control commands.

[0059] S33, the main control unit constructs a transient net efficiency gain index based on the equivalent saved shaft power and active power. This index is used to evaluate the net contribution of the rotary sail to the ship's propulsion energy consumption under the current operating conditions. In each control calculation cycle, the main control unit calculates the algebraic difference between the equivalent saved shaft power and the active power. Considering the potential switching noise and short-term fluctuations in electrical sampling and power calculation, the main control unit performs a sliding window averaging filter on this algebraic difference to generate the net efficiency evaluation index. Its definition logic is as follows: ; In the formula, The transient net performance gain index; The number of sampling points for the sliding window can be set between 10 and 50 cycles, depending on the steady-state response requirements of the control system. for The equivalent shaft power saving calculated at each moment; for The active power is monitored in real time by the system.

[0060] When the index value is greater than zero, it indicates that the propulsion energy gain generated by the rotary sail exceeds the power consumption to maintain its rotation, and the system is in a positive net gain state. When the index value is less than zero, it indicates that the system's own energy consumption exceeds the current propulsion gain. To avoid frequent changes in control state due to power fluctuations in a single sampling period, the main control unit can combine the duration of the sliding window result or set a threshold band for state judgment.

[0061] In the conventional aerodynamic thrust optimization mode, the main control unit uses the transient net efficiency gain index to maintain a positive value or tend to increase as the basis for rotor speed adjustment. When the index is continuously less than zero within the set time window and the ship's roll rate does not reach the mechanical protection threshold, the main control unit reduces the target speed of the rotary sail or switches to a low power consumption maintenance state. When the index returns to a positive value and remains at the set period, the main control unit resumes speed optimization control.

[0062] See attached document Figure 6 To balance mechanical protection, energy feedback, and smooth torque switching during roll excitation enhancement, step S4 can be implemented as follows: S41, the main control unit monitors the ship's roll rate in real time and determines the current wave excitation state and control mode based on the roll rate. In the control state machine, the mechanical safety protection mode has a higher priority than the active gyro roll reduction mode, which in turn has a higher priority than the conventional aerodynamic thrust optimization mode. When the roll rate reaches the structural safety-related threshold, the main control unit prioritizes entering the four-quadrant regenerative power generation and mechanical protection mode; when the roll rate is within the roll reduction allowable range, the decoupling cross-axis current meets the condition of no effective wind load, and the state of charge of the energy storage element meets the discharge condition, the main control unit enters the active gyro roll reduction mode.

[0063] To avoid frequent switching of control modes under critical sea states, the main control unit adopts a dual-threshold judgment method based on a hysteresis comparator. The main control unit extracts the absolute value of the roll rate obtained in step S1 and compares it with the upper and lower threshold judgments. When the absolute value of the roll rate exceeds the upper threshold judgment, the ship is determined to be in a strong roll excitation state, and the control state machine switches from the current operating mode to the four-quadrant regenerative power generation and mechanical protection mode; when the absolute value of the roll rate falls below the lower threshold judgment, the control state machine exits the four-quadrant regenerative power generation and mechanical protection mode, and selects to restore to the conventional aerodynamic thrust optimization mode or switch to the active gyro roll reduction mode based on the decoupled cross-axis current, the state of charge of the energy storage element, and the roll rate duration.

[0064] The upper and lower threshold values ​​are calculated and calibrated based on the target vessel's hydrostatic stability curve, the allowable bending moment of the turbine sail tower, and the bearing capacity of the bottom support structure. Typically, the upper threshold value can be set to 1.2 to 1.5 times the lower threshold value to create a hysteresis range.

[0065] In step S42, after switching to the four-quadrant regenerative power generation and mechanical protection mode, the main control unit calculates the reference value of the reverse electromagnetic damping torque. The reverse electromagnetic damping torque is used to suppress rapid changes in the equivalent dynamic disturbance torque. The main control unit performs discrete difference analysis on the equivalent dynamic disturbance torque obtained in step S2 to obtain the time rate of change of the equivalent dynamic disturbance torque. To reduce the impact of sampling noise and switching noise on the torque command, the main control unit performs a first-order low-pass digital filter on this time rate of change, and then multiplies the filtered result by the negative damping gain coefficient to generate the target electromagnetic damping torque command. Its control law equation is expressed as: ; In the formula, for The target electromagnetic damping torque command generated at any time. This is the damping gain coefficient, which is dynamically limited based on the peak power constraint of the drive motor operating in the four quadrants at the corresponding speed; This represents a first-order low-pass digital filtering function. for The equivalent dynamic disturbance torque at any given moment; This is the equivalent dynamic disturbance torque at the previous sampling time. The sampling time interval is the discrete control cycle.

[0066] During this control process, the four-quadrant frequency converter applies reverse braking torque to the drive motor according to the target electromagnetic damping torque command. When the motor speed direction, electromagnetic torque direction, DC bus voltage, and energy storage element charge state meet the feedback conditions, the drive system enters the regenerative braking quadrant. The alternating load at the bottom of the tower caused by the ship's rolling motion is coupled through the support bearing and the off-center load of the main shaft to form an additional equivalent rotational resistance torque. Under the action of this additional equivalent rotational resistance torque, the drive motor generates regenerative electromagnetic power and feeds electrical energy back to the ship's microgrid.

[0067] When the DC bus voltage or the state of charge of the energy storage element does not meet the feedback conditions, the main control unit limits the reverse electromagnetic damping torque command and restricts the feedback power to avoid DC bus overvoltage or overcharging of the energy storage element.

[0068] S43, the main control unit executes zero torque change rate limiting control. In four-quadrant operation mode, the main control unit superimposes the aerodynamic sustaining torque base value of the rotary sail with the target electromagnetic damping torque command to form the target electromagnetic torque command. Since the damping torque changes with the hull attitude disturbance, the target electromagnetic torque command may switch between positive and negative directions and cross the zero torque position. The aerodynamic sustaining torque base value is determined by the no-load aerodynamic friction resistance corresponding to the current rotational speed of the rotary sail, and can be obtained by looking up a table from a pre-calibrated speed-torque characteristic curve.

[0069] The coupling, transmission connection, or bearing support structure between the motor spindle and the rotating sail may have mechanical clearance or torsional backlash. If the electromagnetic torque reverses too quickly when crossing zero, it can easily cause impact on the transmission chain connection or meshing surfaces. Therefore, the main control unit monitors the target electromagnetic torque command in real time and sets a transmission clearance dead zone on both sides of zero torque according to a preset transmission clearance dead zone threshold, limiting the torque change rate according to a piecewise constraint equation. ; In the formula, The rate of change of the target electromagnetic torque command over time; The actual target electromagnetic torque command value of the previous control cycle; The preset transmission clearance dead zone threshold is calculated and calibrated based on at least one of the following parameters of mechanical transmission chain: coupling torsional clearance, support structure clearance, or tooth clearance. The threshold for the rate of change of the restricted torque within the dead zone; This is the threshold for the rate of change of the conventional physical limit outside the dead zone. To ensure a smooth zero-crossing of the torque, Usually set to 10% to 20%.

[0070] When the target electromagnetic torque command falls into the dead zone of the transmission backlash, the main control unit adopts... Limiting the rate of torque change and reducing the response bandwidth of the current control loop allows the motor rotor to smoothly overcome mechanical backlash, reducing reverse impacts in couplings, transmission connections, or support structures. Once the target electromagnetic torque command leaves the transmission backlash dead zone, the main control unit uses... The corresponding torque change rate is limited to maintain the dynamic response capability of the damping control.

[0071] See attached document Figure 7 To utilize the rotational inertia of the rotary sail for attitude coupling roll reduction when there is no effective wind load and the roll excitation is continuous, step S5 can be implemented as follows: In step S51, the main control unit monitors the decoupled quadrature-axis current and the absolute value of the roll rate in real time to determine whether the system meets the entry conditions for the active gyro-based roll reduction mode. Under conditions of no effective wind field and the presence of long-wave swells, the rotary sail is unlikely to generate effective aerodynamic propulsion. To reduce the impact of short-term gusts or fluctuations in a single sampling period on mode determination, the main control unit calculates the effective value of the decoupled quadrature-axis current obtained in step S2 within a set time window, and calculates the integral value of the absolute value of the roll rate obtained in step S1. This time window can be determined based on the hydrostatic parameters of the target vessel, typically covering 3 to 5 natural roll cycles, for example, 30 to 60 seconds.

[0072] When the effective value of the decoupled cross-axis current is continuously lower than the preset wind load lower limit threshold within a set time window, and the integral value of the absolute value of the roll angular velocity is higher than the preset roll excitation threshold within the same set time window, the main control unit determines that the current working condition is a working condition with no effective wind load and continuous roll excitation.

[0073] Under this condition, if the roll rate does not exceed the upper limit of the mechanical safety protection mode and the state of charge of the energy storage element is higher than the lower limit of the discharge protection mode, the main control unit switches to the active gyro roll reduction mode; if the roll rate exceeds the upper limit of the mechanical safety protection mode, the main control unit prioritizes the execution of the four-quadrant regenerative power generation and mechanical protection modes; if the roll rate does not exceed the upper limit of the mechanical safety protection mode, but the state of charge of the energy storage element does not meet the discharge conditions, the main control unit maintains or switches to the low power maintenance state and prohibits continuous power release in the active gyro roll reduction mode.

[0074] The wind load lower limit threshold can be calibrated in conjunction with the no-load loss current of the drive motor; the roll excitation threshold can be calibrated based on the target ship's natural roll period, allowable roll response amplitude, and roll reduction control triggering requirements. After the main control unit switches to active gyro roll reduction mode, the control objective of the rotary sail is adjusted from aerodynamic thrust optimization to attitude coupling roll reduction.

[0075] During operation in the active gyro roll reduction mode, when the effective value of the decoupled quadrature current is again higher than the wind load lower limit threshold and remains above the set period, the main control unit determines that the external effective wind field has recovered, exits the active gyro roll reduction mode, and returns to the conventional aerodynamic thrust optimization mode. When the state of charge of the energy storage element drops below the discharge protection lower limit threshold, the main control unit exits the active gyro roll reduction mode, stops alternating speed modulation, and enters a low-power maintenance state. When the roll angular velocity exceeds the mechanical protection upper limit threshold, the main control unit exits the active gyro roll reduction mode and prioritizes entering the four-quadrant regenerative power generation and mechanical protection mode.

[0076] S52, after switching to the active gyro anti-roll mode, the main control unit controls the rotor spindle to enter a basic low-speed angular velocity state. Since there is no effective external wind field to provide the hydrodynamic energy to maintain rotation, the main control unit schedules the energy storage element connected to the DC bus of the four-quadrant inverter to release electrical energy. In practice, the energy storage element exchanges energy with the DC bus of the four-quadrant inverter through a controlled bidirectional power conversion circuit; this bidirectional power conversion circuit uploads the DC bus voltage, charging / discharging current, state of charge, and fault status to the main control unit, and performs current-limited charging / discharging according to the main control unit's instructions.

[0077] To ensure the safety of the ship's microgrid and energy storage components, the main control unit collects the state of charge (SOC) of the energy storage components before releasing power. Only when the SOC is higher than the discharge protection lower limit threshold is the energy storage component allowed to supply power to the four-quadrant frequency converter. The four-quadrant frequency converter uses this electrical energy to drive the motor, causing the rotary sail to rotate continuously at a set base low angular velocity.

[0078] The base low-speed angular velocity is determined based on the rated operating angular velocity of the aerostat sail, its moment of inertia, the roll reduction requirements of the target vessel, the allowable torque of the drive motor, and the available discharge power of the energy storage element. In typical applications, the base low-speed angular velocity can be set to 10% to 20% of the rated operating angular velocity of the aerostat sail. This base low-speed rotation provides a basis for the moment of inertia of subsequent gyro compensation, while reducing ineffective energy consumption and bearing wear.

[0079] In S53, the main control unit superimposes an alternating velocity modulation component onto the base low-speed angular velocity to generate a gyroscopic compensation torque for hull attitude coupling and roll reduction. After the spinner sail's angular momentum couples with the hull's attitude angular velocity, an alternating gyroscopic torque is generated in the orthogonal direction. The main control unit adjusts the rotor's spin angular velocity to change the amplitude of the rotor's spin angular momentum, and then adjusts the amplitude and phase response of the alternating gyroscopic torque.

[0080] In the embodiment where the rotor sail's rotation axis is arranged along the Z-axis of the hull, the alternating gyro torque is not directly equivalent to the pure roll control torque around the X-axis of the hull. Instead, it first acts on the attitude coupling direction orthogonal to the hull's attitude angular velocity and the rotor's rotation axis, and then forms an equivalent roll damping component through the rotor sail base, deck reinforcement structure, and hull hydrodynamic restoring force. The main control unit performs discrete difference and low-pass filtering on the roll angular velocity to obtain the roll angular acceleration that reflects the roll change trend.

[0081] As an alternative implementation, when it is necessary to increase the roll damping component, the bottom support structure of the rotary sail can adopt a support base with a preset installation angle, so that the rotor's rotation axis is fixedly offset relative to the Z-axis of the hull, thereby including an effective component around the X-axis of the hull in the alternating gyro torque. In this alternative implementation, the main control unit corrects the rotor's rotation axis direction according to the preset installation angle, and then performs spatial torque calculation. In the implementation without a preset installation angle, the active gyro roll reduction mode mainly forms an equivalent roll damping effect through hull attitude coupling and structural transmission.

[0082] The main control unit multiplies the roll acceleration by a negative roll reduction gain coefficient to generate an alternating velocity modulation component, which is then superimposed on the base low-speed angular velocity. In the specific control process, the main control unit can also combine the low-pass filter phase delay, the ship's natural roll period, and the lag in the propagation swivel structure to perform phase compensation for the alternating velocity modulation component. Specifically, a lead-lag compensation stage is introduced into the discrete control program, using the difference between one-quarter of the natural roll period and the structural propagation delay time as the compensation time constant. This ensures that the gyro compensation torque after structural propagation primarily acts on the phase interval that suppresses roll energy input. The calculation equation for the comprehensive speed command is expressed as follows: ; In the formula, for The overall speed command given to the drive motor at all times; The set baseline low-speed angular velocity; The gain coefficient for sway reduction is used to adjust the feedback strength of the active compensation torque. Its value is dynamically limited by combining the overload capacity of the drive motor and the maximum discharge power of the energy storage element. This is the rate of change of the filtered roll velocity over time, i.e., the roll acceleration.

[0083] To prevent the rotor from unexpected zero-crossing reversal or mechanical overspeed due to excessive alternating modulation components under extreme surge conditions, the main control unit sets a saturation limiter in the control program to limit the comprehensive speed command to between the minimum positive sustaining speed and the maximum allowable mechanical speed.

[0084] The main control unit inputs the limited composite speed command into the speed control loop. The speed control loop generates a quadrature-axis current command based on the deviation between the composite speed command and the rotor's mechanical angular velocity. The current control loop of the four-quadrant inverter then converts the quadrature-axis current command into the corresponding electromagnetic torque output. Therefore, the speed modulation control and quadrature-axis current control in the active gyro roll reduction mode constitute a cascaded control structure of an outer speed loop and an inner current loop.

[0085] When a ship experiences accelerated rolling, the drive motor generates alternating acceleration and deceleration movements while rotating at a low speed, exciting an alternating rigid body gyroscopic torque that matches the ship's attitude motion. This gyroscopic compensation torque is transmitted to the hull via the tower base and, through structural transmission, attitude coupling, and phase compensation, forms an equivalent roll damping compensation torque, thereby reducing the ship's roll response amplitude and weakening continuous swaying.

[0086] To further clarify the implementation process, control logic, and technical effects of the technical solution described in this invention, the following detailed explanation is provided in conjunction with a specific ship application embodiment, supplemented by numerical calculations and experimental verification data.

[0087] See attached document Figure 8 This embodiment uses a 50,000-ton bulk carrier equipped with a single sprocket sail as the application object. The basic physical parameters of the system configuration are as follows: scalar projection of the total moment of inertia matrix of the sprocket sail and rotor. 15000 kg·m 2 The rated working rotor mechanical angular velocity is 20 rad / s, or approximately 190 rpm; the backlash and clearance parameters of the bottom drive train are converted to the dead zone threshold of the transmission clearance. The value is 100 N·m; the drive motor uses a pole pair number 4. Rotor flux It is a 2.5Wb surface-mount permanent magnet synchronous motor; the bearing friction torque coupling coefficient was calibrated by factory dynamometer and radial loading test. Set to 0.03. The upper limit threshold for mechanical safety protection mode set internally by the main control unit is 0.25 rad / s, and the lower limit threshold is 0.18 rad / s; the lower limit threshold for wind load is set to 20A.

[0088] During navigation in normal sea conditions, external wind conditions are favorable and waves are calm. The main control unit synchronously latches data according to step S1 with a sampling period of 1ms. The rotor mechanical angular velocity is extracted at a certain moment. The roll angular velocity output by the inertial measurement unit is 20 rad / s. The original stator quadrature-axis current sampled by the four-quadrant frequency converter is 0.05 rad / s. The value is 150A. Based on step S2, the formula for calculating the scalar projection of the theoretical radial disturbance torque generated by the coupling of the rotor's spin angular momentum and the ship's slight roll is: ; Substituting the extracted data into the formula, the calculated result is 15000 N·m. This disturbance torque is transferred via a second-order elastic structure transfer function. After filtering and attenuation, the equivalent dynamic disturbance torque transmitted to the drive motor shaft end Approximately 1000 N·m. The main control unit executes the decoupling equations to calculate the stator electromagnetic disturbance current component. : ; Substituting the corresponding parameters into the formula, the result is 2A, thus obtaining the decoupled quadrature-axis current. Subtracting 2A from 150A equals 148A. The main control unit substitutes this decoupled quadrature-axis current into step S3 to calculate the equivalent saved shaft power, and after deducting the active power of the inverter, it finds the transient net efficiency gain index. The value remains positive. At this point, the roll rate of 0.05 rad / s is far below the upper limit threshold of 0.25 rad / s, indicating that the system is in conventional aerodynamic thrust optimization mode, continuously providing positive propulsion benefits to the ship.

[0089] As the navigation environment deteriorated to severe wind and sea conditions, the ship's rolling intensified due to shock waves. High-frequency data from the inertial measurement unit showed that the absolute value of the roll angular velocity rapidly increased, reaching 0.28 rad / s. The main control unit determined that this value exceeded the upper limit threshold of 0.25 rad / s and immediately switched to the four-quadrant regenerative power generation and mechanical protection mode according to step S4 logic. The main control unit performed a filtered differential operation on the rapidly increasing equivalent dynamic disturbance torque to calculate the negative target electromagnetic damping torque command. When the system detected that this damping torque command was in the process of crossing zero torque and its absolute value was less than 100 N·m (i.e., falling into the dead zone), the main control unit switched to the restricted torque change rate threshold. The threshold is set to 50 N·m / s; once the torque command leaves this dead zone, the normal physical limit rate of change threshold is restored. The threshold was set to 500 N·m / s. In this mode, the four-quadrant frequency converter generates reverse braking torque under damping command control, absorbs the mechanical excitation energy at the bottom of the tower and feeds it back to the microgrid, effectively suppressing the damage to the tower structure caused by extreme loads, while avoiding gear meshing impact during zero-crossing reversal.

[0090] After the storm center passed, the sea state transitioned to a typical calm, high-wave condition, characterized by long-wave swells but a lack of effective aerodynamic winds. Within a 45-second monitoring window covering four natural roll cycles, the main control unit continuously calculated and found that the effective value of the decoupled quadrature-axis current had dropped to 12A, below the set wind load lower limit threshold of 20A, while the integral value of the roll angular velocity remained high within the same window. After confirming that the energy storage element's state of charge was 65% and above the discharge protection lower limit threshold of 30%, the main control unit switched to the active gyro roll reduction mode according to step S5. The main control unit then scheduled the energy storage element to discharge, maintaining the rotating sail at a basic low angular velocity. The rotational speed is 2 rad / s, which is 10% of the rated speed. Simultaneously, the main control unit multiplies the filtered roll acceleration by a negative roll reduction gain coefficient to generate a speed modulation component, which is then superimposed on the base speed. The bottom-level speed loop drive motor generates alternating acceleration and deceleration movements that are opposite to the ship's roll tendency, stimulating the rigid body gyroscope precession effect and actively outputting anti-roll damping compensation torque, forcing the ship to quickly regain lateral stability.

[0091] To verify the technical effectiveness of this invention, a rigid-flexible coupled dynamic model of the target ship and the rotary sail was constructed on a semi-physical simulation test platform, and a continuous time-domain simulation with multiple sea states for 3000 seconds was performed. Two control strategies were introduced for parallel comparison: the control group adopted a basic vector closed-loop control strategy without disturbance decoupling, dynamic damping protection, or roll reduction function; the experimental group adopted the synergistic intelligent control method described in this invention.

[0092] See attached document Figure 9 From the comparative data and curves output by the experimental verification, we can see that: During the optimization phase in normal sea conditions, the experimental group precisely eliminated the 2A to 5A alternating current interference caused by mechanical swaying, and the evaluation variance of the transient net efficiency gain index was reduced by 82% compared with the control group. This avoided the ineffective oscillation of the speed command, and increased the equivalent net shaft energy saving per unit hour by 4.3%.

[0093] During periods of severe wind and sea conditions, the allowable bending moment at the base of the tower in the control group exhibited severe sinusoidal decay oscillations, with the maximum peak stress reaching 850 kN·m, approaching the mechanical yield limit. In contrast, after switching to the four-quadrant regenerative power generation and mechanical protection mode, the peak stress at the base of the experimental group was limited to below 380 kN·m by applying a reverse electromagnetic damping torque, a reduction of 55.3%. Furthermore, approximately 12 kWh of regenerative energy was fed back to the microgrid throughout the entire operating window. The zero-crossing torque limiting logic ensured that the differential acceleration value of the transmission chain did not experience any hard jumps during the entire switching process.

[0094] During calm, high-wave conditions, the control group, lacking aerodynamic forces, had to shut down, with the vessel relying solely on its own damping to cope with the swell, maintaining a roll angle amplitude of approximately ±8.5°. The experimental group, through micro-speed energy storage and superimposed alternating velocity modulation, continuously generated active gyrocompensation torque, significantly suppressing and converging the ship's roll angle amplitude to within ±5.1°, achieving a roll suppression rate of 40%. These data demonstrate that this invention, while ensuring the physical safety of the equipment, maximizes energy efficiency and comprehensively improves hull attitude under multi-energy flow conditions, possessing significant engineering value.

[0095] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for intelligent control of self-powered ship rotary sails for synergistic efficiency enhancement, characterized in that, include: The three-axis attitude angular velocities, including roll, pitch, and yaw angular velocities, as well as the rotor mechanical angular velocity, rotor position angle, stator direct-axis current, original stator quadrature-axis current, stator direct-axis voltage, and stator quadrature-axis voltage are extracted synchronously according to the sampling period. The rigid body alternating gyroscope torque is calculated using the three-axis attitude angular velocity and the rotor mechanical angular velocity. The attitude coupling is performed in combination with the installation deflection angle. The equivalent dynamic disturbance torque is obtained by filtering through the elastic structure transfer function. This torque is then converted and subtracted from the original stator quadrature axis current to obtain the decoupled quadrature axis current. The equivalent saved shaft power is calculated by using the decoupled quadrature shaft current and rotor mechanical angular velocity, and the difference between the calculated power and the real-time active power is used to generate a transient net efficiency gain index, which serves as the basis for speed adjustment or mode switching. When the absolute value of the roll angular velocity exceeds the upper limit judgment threshold, the derivative of the equivalent dynamic disturbance torque is used to generate the target damping torque command, which is combined with the aerodynamic maintaining torque base value to form the target electromagnetic torque command. The segmented torque change rate limit is executed in the dead interval of the transmission clearance, and the final command is generated and issued for execution. When the effective value of the decoupled quadrature current is lower than the preset wind load lower limit, the integral of the absolute value of the roll angular velocity is higher than the roll excitation threshold but not higher than the upper limit judgment threshold, and the state of charge of the energy storage element is higher than the discharge protection lower limit threshold within the set time window, the active gyroscope roll reduction mode is switched on. The energy storage power drives the motor to superimpose the speed modulation component opposite to the roll angular acceleration on the base low speed. The generated alternating gyroscope torque is transmitted through support, attitude coupling and phase compensation to form an equivalent roll damping compensation torque.

2. The intelligent control method for self-powered and synergistically enhanced efficiency of ship rotary sails according to claim 1, characterized in that, The synchronous extraction of triaxial attitude angular velocity, rotor mechanical angular velocity, rotor position angle, stator direct-axis current, original stator quadrature-axis current, stator direct-axis voltage, and stator quadrature-axis voltage according to the sampling period specifically includes: Distributed clock synchronization is achieved using the industrial Ethernet bus protocol, and synchronization messages are broadcast at fixed intervals to trigger hardware timers to generate interrupts. The system latches the three-axis attitude angular velocity, the rotor mechanical angular velocity, the rotor position angle, the stator direct-axis current, the original stator quadrature-axis current, the stator direct-axis voltage, and the stator quadrature-axis voltage, and configures the same cycle number for matching and alignment of the data obtained by triggering the same synchronization message.

3. The intelligent control method for self-powered and synergistically enhanced efficiency of ship rotary sails according to claim 1, characterized in that, The calculation of the rigid body alternating gyroscope torque using the three-axis attitude angular velocity and the rotor mechanical angular velocity specifically includes: The extracted three-axis attitude angular velocities are constructed into a spatial attitude angular velocity vector, which includes the roll angular velocity around the X-axis of the ship's follower coordinate system, the pitch angular velocity around the Y-axis, and the heave angular velocity around the Z-axis. Based on the extracted rotor mechanical angular velocity, a rotary sail rotation angular velocity vector is constructed. The rotary sail rotation angular velocity vector has an angular velocity component only in the Z-axis direction of the ship's follow-up coordinate system. The spatial attitude angular velocity vector and the rotary sail rotation angular velocity vector are spatially cross-multiplied, and then multiplied by the pre-calibrated rotational inertia matrix of the rotary sail system to obtain the spatial alternating gyroscope torque vector. The scalar projection component of the spatial alternating gyroscope torque vector on the radial plane of the drive motor spindle is extracted as the theoretical radial disturbance torque.

4. The intelligent control method for self-powered and synergistically enhanced efficiency of ship rotary sails according to claim 3, characterized in that, The process of obtaining the equivalent dynamic disturbance torque through elastic structure transfer function filtering specifically includes: The bilinear transform method is used to discretize the pre-defined second-order elastic structure transfer function in the Laplace domain into a pulse transfer function in the Z domain, and then convert it into a time-domain difference equation. The equivalent dynamic disturbance torque is obtained by substituting the theoretical radial disturbance torque values ​​at the current and historical moments into the time-domain difference equation for iterative calculation.

5. The intelligent control method for self-powered and synergistically enhanced efficiency of ship rotary sails according to claim 4, characterized in that, The process of converting it into a stator electromagnetic disturbance current component and subtracting it from the original stator quadrature-axis current to obtain the decoupled quadrature-axis current specifically includes: The equivalent dynamic disturbance torque is multiplied by the pre-calibrated bearing friction torque coupling coefficient, and then divided by the product of the number of pole pairs of the drive motor, the rotor flux linkage, and the constant 1.5 to obtain the stator electromagnetic disturbance current component. The subtraction decoupling equation is executed in the vector control loop to obtain the decoupled cross-axis current by subtracting the stator electromagnetic disturbance current component from the original stator cross-axis current.

6. The intelligent control method for self-powered and synergistically enhanced efficiency of ship rotary sails according to claim 1, characterized in that, The process of calculating the equivalent shaft power saving using the decoupled quadrature-axis current and the rotor mechanical angular velocity, simultaneously calculating the real-time interactive active power, and obtaining the difference between the two to generate the transient net efficiency gain index specifically includes: Substituting the decoupled cross-axis current and the rotor mechanical angular velocity into the function mapping relationship obtained by joint calibration through wind tunnel test data and ship hydrodynamic data, the equivalent shaft power saving is calculated. Based on the instantaneous power relationship in the synchronous rotating coordinate system, the active power is calculated using the stator direct-axis voltage, the stator quadrature-axis voltage, the stator direct-axis current, and the original stator quadrature-axis current. The algebraic difference between the equivalent saved shaft power and the active power is calculated, and a sliding window averaging filter is applied to the algebraic difference to generate the transient net efficiency gain index.

7. The intelligent control method for self-powered and synergistically enhanced efficiency of ship rotary sails according to claim 1, characterized in that, The step of generating the target electromagnetic damping torque command using the derivative of the equivalent dynamic disturbance torque specifically includes: The time rate of change of the equivalent dynamic disturbance torque is obtained by discretizing the equivalent dynamic disturbance torque; The time rate of change of the equivalent dynamic disturbance torque is subjected to a first-order low-pass digital filter, and the filtered result is multiplied by the negative damping gain coefficient to generate the target electromagnetic damping torque command. The target electromagnetic damping torque command is formed by superimposing the target electromagnetic torque command with the aerodynamic sustaining torque base value of the rotary sail.

8. The intelligent control method for synergistic efficiency enhancement of ship rotary sail self-powered system according to claim 7, characterized in that, The step of limiting the piecewise nonlinear torque change rate based on the dead interval of the transmission gap where the current target electromagnetic torque command is located specifically includes: The target electromagnetic torque command is monitored in real time, and the transmission gap dead zone is set on both sides of zero torque according to the preset transmission gap dead zone threshold. When the target electromagnetic torque command falls into the dead zone of the transmission gap, a limited torque change rate threshold is used to limit the torque change rate and reduce the response bandwidth of the current control loop. When the target electromagnetic torque command leaves the transmission gap dead zone, the torque change rate is limited by a conventional physical limit change rate threshold. The restricted torque change rate threshold is less than the conventional physical limit change rate threshold.

9. The intelligent control method for synergistic efficiency enhancement of ship rotary sail self-powered system according to claim 1, characterized in that, The condition for determining when the decoupled cross-axis current approaches zero and the integral value of the absolute value of the roll angular velocity is higher than the preset roll excitation threshold is as follows: The effective value of the decoupled cross-axis current is calculated within a set time window, and the integral value of the absolute value of the roll angular velocity within the same time window is also calculated. When the effective value of the decoupled cross-axis current is continuously lower than the preset wind load lower limit threshold, and the integral value of the absolute value of the roll angular velocity is higher than the preset roll excitation threshold, it is determined that the decoupled cross-axis current is close to zero and the integral value of the absolute value of the roll angular velocity is higher than the preset roll excitation threshold. If the absolute value of the roll angular velocity does not exceed the upper limit threshold and the state of charge of the energy storage element is higher than the lower limit threshold of the discharge protection, then the active gyroscope roll reduction mode is switched to.

10. The intelligent control method for self-powered and synergistically enhanced efficiency of ship rotary sails according to claim 9, characterized in that, The method of using energy storage elements to drive a motor in a basic low-speed rotational state, superimposed with a speed modulation component that is inversely phase to the roll angle acceleration, specifically includes: The energy storage element is scheduled to release electrical energy to maintain the basic low-speed rotation state at a basic low-speed angular velocity. The roll angular velocity is discretely differentially analyzed and low-pass filtered to obtain the roll angular acceleration. The roll angular acceleration is then multiplied by a negative roll reduction gain coefficient to generate the velocity modulation component. The velocity modulation component is superimposed on the basic low-speed angular velocity to form a comprehensive velocity command. The combined speed command is then input into the speed control loop after being limited by a saturation limiter to between the minimum positive sustaining speed and the maximum allowable mechanical speed.

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