Wind power installation vessel hoisting platform stability control method based on multi-motor different-speed cooperation

Abstract

The invention provides a wind power installation vessel hoisting platform stability control method based on multi-motor different-speed cooperation, which comprises the following steps: calculating the distribution pressure of four pile feet under a statically stable structure of an offshore wind power installation vessel hoisting platform, and calculating the lifting speed required by the pile feet according to the actual pressure value and the distribution pressure value; if the four pile feet have different lifting speeds and the lifting speeds exceed the adjustable range of the pile feet, the distributed lifting speed of each pile foot is calculated by taking the minimum change of the gravity center of the hoisting platform as a target; and designing a rotating speed cooperative control system based on a No.0 virtual driving motor to realize cooperative control of the distributed lifting speed of each pile foot, wherein the rotating speed cooperative control system comprises a feedback compensation module. By means of the method, the multi-pile-foot and multi-motor different-speed cooperative control problem can be effectively solved, and balance and stability of the hoisting platform are achieved.

Description

Technical Field

[0001] The present invention belongs to the field of multi-motor collaborative control methods, and particularly relates to a stability control method applied to a hoisting platform of a wind power installation ship. Background Art

[0002] Under the dual pressures of the shortage of conventional energy and the deterioration of the global ecological environment, wind energy, as a new type of pollution-free and renewable energy, has great development potential. Most of the regions with the richest wind resources in the world are distributed at sea. In terms of the distribution of wind energy resources in China, the regions with the richest wind energy in China are distributed along the southeast coast and its nearby islands. The exploitable wind energy reserves in the offshore area are about 750 million kilowatts, which is about three times that of the exploitable wind energy on land. The offshore wind power installation ship is the key to installing offshore wind turbines and effectively utilizing marine wind energy. At present, offshore wind power installation equipment includes self-elevating offshore wind power installation ships, which are composed of hulls, thrusters, pile legs, lifting devices, etc. During offshore operations, the pile legs rotate to the working position perpendicular to the hull, and each pile foot is rammed into the seabed through the lifting device of each pile foot. The lifting devices of all pile feet are adjusted to lift the hull to the required height. During this process, the lifting devices bear huge alternating loads.

[0003] When installing wind power, the hull needs to be lifted to a certain height. However, different degrees of looseness of the seabed soil will result in the same pile driving speed not being able to ensure the stability of the platform. Therefore, it is necessary to dynamically adjust the pile driving and pile lifting speeds of the pile feet according to the actual situation. This situation involves the asynchronous collaborative control of multi-pile foot drive motors. The common methods of multi-motor asynchronous collaborative control are as follows:

[0004] (1) Master-slave control

[0005] In the master-slave control structure, the system sends speed signals from the master motor to each slave-axis motor and transmits them step by step. During this process, the actual speed of the previous-stage motor is used as the reference speed of the subsequent motor, and there is no signal coupling between the motors. However, this control method is a cascade control structure, and the breakdown of any link will affect the control of all subsequent motors. In addition, it is difficult to set different given speeds for the drive motors with this method. Therefore, it is not applicable to asynchronous collaborative occasions.

[0006] (2) Cross-coupling control

[0007] In cross-coupling control, the speeds or positions of two adjacent motors are compared, and the difference between them is fed to the controller to readjust the feedback signal of speed tracking. Cross-coupling control comprehensively considers the influence of the speed changes of each motor on the system and is applicable to asynchronous collaborative occasions. However, since this method needs to consider the influence of each motor on the system at the same time, when the number of drive motors is more than 3, the coupling of the control method is extremely strong and the system stability is poor.

[0008] (3) Coupling control based on virtual spindle

[0009] For the coupling control based on virtual spindle, a virtual motorized spindle is set up, which aggregates the influence of the rotational speed difference and torque difference of all motors on the system, and then distributes it to each driving motor, so as to adjust the given rotational speed of the motor. This method achieves a balance between system decoupling and cross influence, and thus is also applicable to the occasion of asynchronous cooperation. However, there is currently a lack of research on the virtual spindle control method applied to the asynchronous cooperation of 12 motors on the wind power installation vessel. Summary of the Invention

[0010] Aiming at the deficiencies existing in the prior art, the present invention provides a stable control method for the hoisting platform of a wind power installation vessel based on the asynchronous cooperation of multiple motors.

[0011] The present invention realizes the above technical objectives through the following technical means.

[0012] The stable control method for the hoisting platform of a wind power installation vessel based on the asynchronous cooperation of multiple motors includes:

[0013] Calculating the distribution pressure of the four pile legs under the statically determinate and stable structure of the hoisting platform of the offshore wind power installation vessel, and calculating the required lifting speed of the pile legs through the actual pressure value and the distribution pressure value;

[0014] If the four pile legs have different lifting speeds and there is a lifting speed exceeding the adjustable range of the pile legs, calculating the distribution lifting speed of each pile leg with the minimum change of the center of gravity of the hoisting platform as the target;

[0015] Designing a rotational speed coordination control system based on the No. 0 virtual drive motor to realize the coordinated control of the distribution lifting speed of each pile leg, and the rotational speed coordination control system includes a feedback compensation module.

[0016] Furthermore, the actual pressure value is detected by a pressure sensor installed on the pile leg.

[0017] Furthermore, the specific calculation formula for the distribution lifting speed is:

[0018]

[0019] Wherein, F pre-A is the distribution pressure of pile leg A, F pre-B is the distribution pressure of pile leg B, F pre-C is the distribution pressure of pile leg C, F pre-D is the distribution pressure of pile leg D; F A-real is the actual pressure of pile leg A, F B-real is the actual pressure of pile leg B, F C-real is the actual pressure of pile leg C, F D-real is the actual pressure of pile leg D; Fmax is the maximum pressure difference between pile feet, F min is the minimum pressure difference between pile feet, F ave is the average value of the maximum and minimum pressure differences between pile feet, n’ X is the assigned lifting and lowering speed of pile foot X, F X-real is the actual pressure of pile foot X, where X is the pile foot number and X = A, B, C, D; m is the mass of the offshore wind power installation vessel, and Δt is the time length of the discrete time segment in the balance control period.

[0020] Furthermore, the No. 0 virtual drive motor constructs the parameters of the No. 0 virtual drive motor by collecting the real-time feedback speeds of the No. 1-12 actual drive motors. The parameters of the No. 0 virtual drive motor include the input quantity of the torque control current of the No. 0 virtual drive motor and the output quantity of the speed of the No. 0 virtual drive motor.

[0021] Furthermore, the speed unit of the speed collaborative control system includes a hybrid speed setting link, a controller for a single drive motor, a simplified model of an inverter, a torque mixing link, and a mathematical model of a drive motor.

[0022] Furthermore, the hybrid speed includes the given speed of the electric rack and pinion lifting device, the real-time feedback speed of the current drive motor, and the output speed of the No. 0 virtual drive motor.

[0023] Furthermore, the given speed of the electric rack and pinion lifting device is the assigned lifting and lowering speed of the current pile foot, and the output speed of the No. 0 virtual drive motor is the output quantity of the speed of the No. 0 virtual drive motor.

[0024] Furthermore, the feedback compensation module includes the pile foot compensation coefficient designed by the feedback compensation module and the compensation coefficient of the actual drive motor in the electric rack and pinion lifting device of the pile foot designed by the feedback compensation module.

[0025] Furthermore, the calculation of the pile foot compensation coefficient is specifically as follows:

[0026] According to the sum of the actual pressures of the four pile feet tending to the gravity and the sum of the actual torques of the four pile feet tending to zero, the minimum deviation between the sum of the actual pressures of the four pile feet and the gravity of the lifting platform is obtained; the difference between the actual pressure of the pile foot and the minimum deviation is calculated, and the compensation coefficient of the pile foot can be obtained according to the ratio of the difference to the actual pressure of the pile foot.

[0027] Furthermore, the calculation of the compensation coefficient of the actual drive motor in the electric rack and pinion lifting device of the pile foot is specifically as follows:

[0028] First, determine whether the failure motor number i in the electric rack and pinion lifting device is even or odd; secondly, stop the drive motors at the symmetrical positions of the failure motors of the electric rack and pinion lifting device; finally, calculate the compensation coefficient of the actual drive motors in the pile leg electric rack and pinion lifting device according to the ratio of the driving force of the actually participating drive motors to the driving forces of the 12 drive motors in the lifting device.

[0029] The beneficial effects of the present invention are as follows:

[0030] (1) Compared with the existing multi-motor same-speed control, the lifting speeds of the 4 pile legs of the present invention are not necessarily the same, and are set in real time according to the platform stability state.

[0031] (2) Compared with the general multi-motor different-speed cooperative control, the present invention aims to minimize the change of the center of gravity of the hoisting platform after imbalance, sets the pressure adjustment targets for the four pile legs of the hoisting platform, and uses them to correct the pile leg distribution speeds, so as to ensure that the balance change of the hoisting platform is always within the specified threshold.

[0032] (3) Compared with the general multi-motor different-speed cooperative control based on the virtual main shaft, the present invention pays more attention to the balance and stability of the hoisting platform. Therefore, a speed feedback compensation module is designed, and the source of the mixed speed of the lifting device in the multi-motor different-speed cooperation is further elaborated. Description of the Drawings

[0033] Figure 1 It is a schematic diagram of the forces on the seabed when the pile of the hoisting platform of the present invention is landed;

[0034] Figure 2 It is a schematic diagram of the speed cooperative control system of 12 motors of the electric rack and pinion lifting device of the present invention;

[0035] Figure 3 It is a block diagram of the balance and stability control method of the hoisting platform of the offshore wind power installation ship of the present invention. Detailed Embodiments

[0036] The following further illustrates the present invention in conjunction with the drawings and specific embodiments, but the protection scope of the present invention is not limited thereto.

[0037] A stability control method for the hoisting platform of an offshore wind power installation ship based on multi-motor different-speed cooperation of the present invention specifically includes the following steps:

[0038] Step 1, calculate the pressures of the four pile legs when the hoisting platform of the offshore wind power installation ship is stable

[0039] Such as Figure 1As shown, the center of gravity of the offshore wind power installation ship is irregularly and arbitrarily distributed in the lifting platform. As long as the platform maintains a statically stable structure, the center of gravity will not shift during transportation and lifting. At this time, the lifting platform is stable and will not cause the wind power installation ship to capsize. The lifting platform can be simplified as a rectangular platform, with piles A, B, C, and D installed at the four corners of the platform. The position of the pile D in the lower left corner is the origin O of the plane coordinate system, the DC direction is the x-axis of the plane coordinate system, and the DA direction is the y-axis of the plane coordinate system. Suppose the current center of gravity position of the offshore wind power installation ship lifting platform is G(x, y), and the length of the lifting platform is S L , width is S W . Generally, the seabed in the sea area where offshore wind power is installed is an irregular seabed, and the soil quality of the seabed is of different consistency and the topography is different. Therefore, when the pile feet of the lifting platform are lowered to bring the hull onto the platform, there is a process of pre-pressing the pile feet, which presses the soil to prevent sudden loosening and causing the hull to capsize. However, the uneven distribution of the seabed soil or the empty shell on the seabed will cause the pressure of the pile feet to change, resulting in the same lifting speed of the pile feet being unable to maintain the stability and balance of the lifting platform, thereby causing the lifting platform to be unbalanced or even the capsizing of the self-elevating offshore wind power installation ship. Therefore, the present invention installs pressure sensors on the four pile feet to sense the changes in pressure. Once the empty shell on the seabed breaks and causes a pile foot to lose pressure or a pile foot presses the rock to increase the pressure locally, the system can adjust the lifting speed of the four pile feet in time to ensure the balance between the hull and the lifting platform.

[0040] Assuming the gravity G' of the hoisting platform of the offshore wind power installation ship, when the four piles of the offshore wind power installation ship are pressed tightly, the offshore wind power installation ship is in a statically stable structure. At this time, the distribution pressure of the piles A, B, C, and D is:

[0041]

[0042] Among them, F pre-A is the pressure at the pile foot A, F pre-B is the pressure at the pile foot B, F pre-C is the pressure at the pile foot C, F pre-D is the pressure at the pile foot D; x and y are the horizontal and vertical coordinates of the center of gravity G in the plane coordinate system with the origin O; S L , S W They are the length and width of the lifting platform of the offshore wind power installation vessel respectively.

[0043] Step 2: Calculate the required lifting speed of each pile foot according to the current status of the wind turbine installation ship hoisting platform

[0044] The actual pressure of the pile foot is detected by the pressure sensor installed at each pile foot, and the actual pressure value is compared with the pressure value of the pile foot under the statically stable structure in step 1, and the difference is converted into the required lifting speed of the pile foot. The specific calculation formula is:

[0045]

[0046] Among them, n A 、n B 、n C 、n D are the lifting speeds of pile feet A, B, C, and D respectively, m is the mass of the offshore wind power installation vessel, and F pre-X is the distributed pressure of pile foot X, and F X-real is the actual pressure of pile foot X, n X is the lifting speed of pile foot X, and Δt is the time length of the discrete time segment in the control period.

[0047] (1) When the lifting platform is stable and balanced, at this time F pre-A = F A-real , F pre-B = F B-real , F pre-C = F C-real , F pre-D = F D-real , indicating that the offshore wind power installation vessel is in a statically stable structure at this time. At this time, the lifting speeds of the four pile feet are the same, and n A = n B = n C = n D .

[0048] (2) When the lifting platform is unbalanced, F pre-X ≠ F X-real , that is, the distributed pressure of any pile foot is not equal to the actual pressure, indicating that the offshore wind power installation vessel is out of balance and is no longer in a statically stable structure state. At this time, it is necessary to adjust the lifting speeds of the pile feet to restore or maintain the balance state as much as possible.

[0049] Step 3, when the lifting platform is out of balance, calculate the control input lifting speed of the stable lifting platform

[0050] When the lifting platform of the offshore wind power installation vessel is out of balance, it is necessary to dynamically adjust the lifting speeds of each pile foot to make the platform restore balance. At this time, it is possible that the four pile feet have different lifting speeds, and some of the lifting speeds exceed the adjustable range of the pile feet. The present invention calculates the control input lifting speed of the stable lifting platform according to the principle of minimizing the change in the center of gravity.

[0051] Step 3.1, determine the range of pile foot lifting speed

[0052] According to the actual rising / falling speed and acceleration limit of the electric gear rack lifting device in the pile foot, limit the maximum values of the pile foot lifting speed and acceleration:

[0053]

[0054] Among them, n X is the lifting speed of any pile leg, and a X is the lifting acceleration of any pile leg. The lifting speed n of the pile leg X and the acceleration a X need to be within the specified thresholds n max and a max . The upper limits of the speed and acceleration thresholds are determined by the mechanical strength of the electric rack and pinion lifting device.

[0055] Step 3.2, Coordinate the lifting speed of the pile legs under the balanced lifting platform

[0056] When the four pile legs have different lifting speeds, with the goal of minimizing the change in the center of gravity of the lifting platform after imbalance, that is, by comparing the pressures distributed by the statically stable structures of pile legs A, B, C, and D with the actually measured pile leg pressures, select the maximum and minimum pressure differences, so as to set the pressure adjustment target F of the four pile legs of the lifting platform ave .

[0057]

[0058] Among them, F max is the maximum pressure difference of the pile legs, F min is the minimum pressure difference of the pile legs, and F ave is the average value between the maximum and minimum pressure differences of the pile legs, which is also the pressure adjustment target of the four pile legs of the lifting platform.

[0059] Therefore, the assigned lifting speeds of each pile leg are as follows:

[0060]

[0061] Among them, n’ A , n’ B , n’ C , n’ D are the assigned lifting speeds of pile legs A, B, C, and D.

[0062] Step 4, Design the rotational speed coordination control system for a single set of electric rack and pinion lifting devices in a single pile leg

[0063] Each pile leg has 3 sets of electric rack and pinion lifting devices, and each set of electric rack and pinion lifting devices contains 12 actual driving motors. To ensure that the pile leg does not undergo mechanical deformation during the lifting process, resulting in pile leg failures and affecting its supporting performance, the lifting speeds and directions of these 3 sets of electric rack and pinion lifting devices are consistent with the pile leg. Therefore, design a rotational speed coordination control system for the electric rack and pinion lifting device containing 12 driving motors. In the rotational speed coordination control system for the electric rack and pinion lifting device containing 12 driving motors, there are two control requirements:

[0064] (1) The rotational speeds of the drive motors are consistent

[0065] The rotational speeds of 12 drive motors maintain consistency in speed and direction, thus ensuring consistent rack lifting and lowering speeds;

[0066] (2) The torques of the drive motors are as consistent as possible

[0067] 12 drive motors drive gears to drive the rack to lift and lower. The torques of the motors need to be as consistent as possible to ensure uniform force on the gears.

[0068] Taking the electric gear-rack lifting device a of pile foot A as an example for explanation. The allocated lifting and lowering speed of pile foot A is n' A , when ignoring the faults or differences of the electric gear-rack lifting devices, the given rotational speeds of the three groups of electric gear-rack lifting devices a, b, and c are n A-a = n A-b = n A-c = n' A . The specifications of the drive motors in the device are the same, and the moments of inertia J m of its 12 drive motors are the same, and the given rotational speed of each motor is also the same. Figure 2 The dash-dotted part in the middle is a rotational speed unit of the rotational speed coordination control system, which is composed of a hybrid rotational speed given link, a controller for a single drive motor, a simplified model of an inverter, a torque mixing link, and a mathematical model of the drive motor. The hybrid rotational speed given link combines the given rotational speed n A-a of the electric gear-rack lifting device, the real-time feedback rotational speed n A-a-x (the feedback rotational speed can be measured and read in real time through a rotational speed sensor) of the current drive motor, and the output rotational speed n vir-A-a of the No. 0 virtual drive motor, and calculates the differential speed e A-a-x of the current drive motor. This differential speed is input into the controller as the input quantity of the single drive motor controller for calculation, and the control quantity u A-a-x calculated by the single drive motor controller is input into the simplified model of the inverter to calculate the electromagnetic torque F eA-a-x output by a single rotational speed unit. When the device is running, external interference will be applied to any drive motor as interference torque F LA-a-x , and the torque dragging the drive motor to rotate is the difference between the electromagnetic torque T eA-a-x and the interference torque T LA-a-x . Figure 2 The bold two-dash part in the middle is the No. 0 virtual drive motor, whose structure is similar to that of the rotational speed unit, but it collects the real-time feedback rotational speeds of all actual drive motors, thereby constructing virtual drive motor parameters (torque constant control module based on the No. 0 virtual drive motor) to balance the system deviation.

[0069] Step 5, design a torque constant control module based on the virtual drive motor No. 0

[0070] Step 5.1, torque control equation of a single drive motor

[0071] In this embodiment, a three-phase asynchronous motor is selected as an example for illustration. The current-torque control equations of other types of rotating drive motors are similar and not limited to the motor type. Ignoring the armature inductance of the motor and the friction of the motor drive shaft, the torque drive equation can be simplified as:

[0072]

[0073] In formula (6), F eA-a-x is the electromagnetic torque of the x-th drive motor of the electric rack and pinion lifting device a of pile leg A, where x = 1, 2, 3,..., 12; F LA-a-x is the load torque of the x-th drive motor of the electric rack and pinion lifting device a of pile leg A; n A-a-x is the rotational speed of the x-th drive motor of the electric rack and pinion lifting device a of pile leg A; GD 2 is the flywheel inertia of the drive motor.

[0074] Step 5.2, calculate the torque control current input of the virtual drive motor No. 0

[0075] The torque of the virtual drive motor No. 0 is essentially the set of the 1-12th drive motors of the electric rack and pinion lifting device a of pile leg A. The equation for obtaining the torque F eA-a-vir of the virtual drive motor No. 0 is:

[0076]

[0077] In formula (7), GD x 2 is the flywheel inertia of the x-th drive motor. In addition, a three-phase asynchronous motor is also selected as the type of the virtual drive motor, and the torque control equation of the virtual drive motor No. 0 is written as:

[0078]

[0079] In formula (8), n pA-a is the number of pole pairs of the virtual drive motor No. 0, and its number of pole pairs is the same as that of the actual drive motor. L mA-a is the stator inductance of the virtual drive motor No. 0, L rA-a is the rotor inductance of the virtual drive motor No. 0, ψ rA-a is the rotor flux linkage of the virtual drive motor No. 0, and i stA-a is the control current required to obtain the torque F eA-a-vir of the virtual drive motor No. 0.

[0080] Combining formula (7) and formula (8), it can be seen that the torque F of the virtual drive motor No. 0 needs to be achieved eA-a-vir output, which controls the current i stA-a for:

[0081]

[0082] Step 5.3, calculate the speed output of the virtual drive motor No. 0

[0083] When the virtual drive motor No. 0 is a three-phase asynchronous motor, its slip angular velocity ωs A -a-vir is:

[0084]

[0085] Rr in formula (10) A -a is the rotor resistance of the virtual drive motor No. 0. At this time, the angular speed output of the virtual drive motor No. 0 is ω A -a-vir is:

[0086]

[0087] Among them, ω 1A -a-vir is the synchronous angular velocity, and f is the input current frequency.

[0088] Converting formula (11) into speed output form, the speed output of virtual drive motor No. 0, nvir- A -a means:

[0089]

[0090] Step 6: Feedback the actual speed of the virtual drive motor No. 0 and the actual drive motors No. 1-12 to the speed coordination control module of the electric gear rack lifting device

[0091] like Figure 2 As shown, the input of the speed coordination control module is essentially to set the electric gear rack lifting device to a given speed n A -a, Output speed of virtual drive motor No. 0 after feedback compensation nvir- A -a and feedback speed n of the actual drive motors No. 1-12 A -ax input controller unit. The feedback compensation module includes the compensation coefficient of the designed feedback compensation module pile foot and the compensation coefficient of the actual driving motor in the designed feedback compensation module pile foot electric gear rack lifting device.

[0092] Step 6.1, design feedback compensation module

[0093] The input value of the feedback compensation module is the output speed of the virtual drive motor No. 0, nvir-A -a and the current actual feedback rotational speed n of the driving motor A -a - x, and its compensation calculation is as follows:

[0094] n A -a - xcom = k A k A -a - x(nvir - A -a - n A -a - x)(13)

[0095] In formula (13), n A -a - xcom is the output of the feedback compensation module, and k A is the compensation coefficient of pile leg A, which can correct the lifting speeds of the four pile legs, or redistribute the lifting speeds of pile legs A, B, C, and D when a certain pile leg fails. k A -a - x is the compensation coefficient of the xth actual driving motor of the electric rack and pinion lifting device of pile leg A, which can correct the speeds of the 12 actual driving motors in the electric rack and pinion lifting device.

[0096] Step 6.2, design the pile leg compensation coefficient of the feedback compensation module

[0097] The restoration target when the hoisting platform is in a statically stable structure or an unbalanced state, that is, to make the sum of the actual pressures of the four pile legs tend to the gravity, and the sum of the actual torques of the four pile legs tend to zero. The formula is as follows:

[0098]

[0099] In formula (14), t is time, F A-real is the actual pressure of pile leg A, F B-real is the actual pressure of pile leg B, F C-real is the actual pressure of pile leg C, F D-real is the actual pressure of pile leg D; G’ is the gravity of the hoisting platform; l AG is the lever arm from the center of gravity G to pile leg A, l BG is the lever arm from the center of gravity G to pile leg B, l CG is the lever arm from the center of gravity G to pile leg C, l DG is the lever arm from the center of gravity G to pile leg D.

[0100] The process from losing balance to restoring stability is a gradually stable process, and the overall control target during this process is as shown in formula (15):

[0101]

[0102] Formula (15) is the optimal value function for restoring the stability of the hoisting platform. During the process of adjusting the hoisting platform of the wind power installation vessel from an unbalanced state to a statically determinate stable structure, it is actually a process of obtaining the minimum value F of the deviation between the total actual pressure of the four pile feet and the gravity of the hoisting platform min , and the minimum value T of the total pile foot moment min .

[0103] According to the minimum value F of the deviation between the total pile foot pressure and the gravity min , and the actual pressure A of the pile foot, the compensation coefficient k of pile foot A can be obtained A :

[0104]

[0105] Step 6.3, design the compensation coefficient of the actual drive motor in the pile foot electric gear rack lifting device

[0106] If there is a drive motor failure in the electric gear rack lifting device, the failed drive motor will affect the mechanical telescopic structure in the electric gear rack lifting device. In severe cases, it will cause the rack to bend and the device to fail. Therefore, when designing the compensation coefficient, it is necessary to determine the number of the failed motor and stop the drive motor at the symmetrical position, and then design the compensation coefficient. Similarly, assume that the i-th drive motor in the electric gear rack lifting device a of pile foot A fails.

[0107] (1) Determine whether the number i of the failed motor in the electric gear rack lifting device is even or odd

[0108]

[0109] (2) Stop the drive motor at the symmetrical position of the failed motor in the electric gear rack lifting device

[0110]

[0111] If one drive motor fails in the electric gear rack lifting device, it is necessary to stop the drive motor at the symmetrical position on the other side in time. Otherwise, the rack is prone to uneven stress and deformation or breakage during the lifting process. Formulas (17) and (18) are used to determine the number of the failed drive motor in this fault situation.

[0112] (3) The compensation coefficient of the actual drive motor in the pile foot electric gear rack lifting device

[0113]

[0114] In formula (19), the compensation coefficient k A-a-xIt is the ratio of the driving force of the driving motor actually participating in the work to the driving forces of the 12 driving motors in the lifting device. Since the motor model parameters are all the same, and once a motor fails, the driving motor at the symmetric position of that motor needs to be stopped. Therefore, for each failed driving motor, the driving force loss is 2F A-a-i In addition, the failure situation is random and unpredictable. Therefore, the driving force of the driving motor actually participating in the work needs to subtract twice the driving force of all failed driving motors, that is, it needs to subtract ∑2F A-a-i .

[0115] Step 7, Overall framework of the stability control method for the hoisting platform of a wind power installation ship based on multi-motor asynchronous coordination

[0116] Steps 4-6 are only illustrated by taking the electric rack and pinion lifting device a of pile leg A as an example. The electric rack and pinion lifting devices of any pile leg are the same. Thus, combined with steps 1-6, the overall framework of the stability control method for the hoisting platform of a wind power installation ship based on multi-motor asynchronous coordination is designed, as Figure 3 shown. The hoisting platform has 4 pile legs, each pile leg has 3 groups of electric rack and pinion lifting devices, and each electric rack and pinion lifting device is composed of 12 driving motors inside. The 3 groups of electric rack and pinion lifting devices are arranged in an equilateral triangle to ensure the mechanical rigidity of the pile leg. The allocated lifting speed n' of the pile leg X , the speed compensation coefficient of each pile leg is k X , and the speed compensation coefficients of the actual driving motors of the electric rack and pinion lifting devices a, b, and c of each pile leg are k X-a-x , k X-b-x , k X-c-x respectively. The specific implementation steps are as follows:

[0117] First, calculate the allocated pressures of the four pile legs when the hoisting platform of the offshore wind power installation ship is stable (step 1); take the allocated pressures of the pile legs as the comparison reference values, detect the actual pressures of the pile legs through the pressure sensors installed on the pile legs, and compare them with the allocated pressures to judge whether the hoisting platform of the offshore wind power installation ship is balanced. If it is not balanced, then convert the allocated pressures into the required lifting speeds of the pile legs (step 2); if the four pile legs have different lifting speeds, and some of the lifting speeds exceed the adjustable range of the pile legs, according to the principle of the smallest change in the center of gravity, correct the control input lifting speeds for stabilizing the hoisting platform (step 3).

[0118] Secondly, during the process of adjusting the lifting speed of the pile feet on the hoisting platform, for each pile foot, it is necessary to design a rotational speed coordination control system for its electric gear-rack lifting device (step 4) to ensure that the rotational speeds of the driving motors are consistent and the torques of the driving motors are as consistent as possible; at the same time, there is a virtual driving motor numbered 0 in the rotational speed coordination control system (step 5). This virtual driving motor collects the rotational speeds of the actual driving motors numbered 1-12 and outputs a fitted rotational speed, which is used to feedback to the actual driving motors numbered 1-12 as a part of the value for correcting the rotational speed.

[0119] Finally, to achieve the multi-pile-foot different-speed coordination control, after compensating the output rotational speed of the virtual driving motor numbered 0 and the actual rotational speeds of the actual driving motors numbered 1-12, they are feedback to the rotational speed coordination control system of the electric gear-rack lifting device, and combined with the given rotational speed n of the electric gear-rack lifting device A-a as the input of the actual driving motor controller. Among them, the compensation processing includes designing the pile foot compensation coefficient of the feedback compensation module and the compensation coefficient of the actual driving motor in the pile foot electric gear-rack lifting device of the feedback compensation module (step 6).

[0120] The above embodiments are the preferred embodiments of the present invention, but the present invention is not limited to the above embodiments. Without departing from the essence of the present invention, any obvious improvements, substitutions or modifications that those skilled in the art can make all fall within the protection scope of the present invention.

Claims

1. A stable control method for a hoisting platform of a wind power installation vessel based on multi-motor different speed coordination, characterized in that: Calculate the distributed pressure of the four piles under the statically stable structure of the offshore wind power installation ship hoisting platform, and calculate the required lifting speed of the piles through the actual pressure value and the distributed pressure value; If the four piles have different lifting speeds, and one of the lifting speeds exceeds the adjustable range of the pile, the allocated lifting speed of each pile is calculated with the goal of minimizing the change in the center of gravity of the lifting platform; A speed coordinated control system based on No. 0 virtual drive motor is designed to realize the coordinated control of the distributed lifting speed of each pile foot. The speed coordinated control system includes a feedback compensation module.

2. The method for controlling the stability of a wind power installation vessel hoisting platform based on multi-motor different speed coordination according to claim 1 is characterized in that: The actual pressure value is obtained by detecting a pressure sensor installed at the pile foot.

3. The method for controlling the stability of a wind power installation vessel hoisting platform based on multi-motor different speed coordination according to claim 1 is characterized in that: The specific calculation formula for the distribution lifting speed is: Among them, F pre-A is the distributed pressure of pile foot A, F pre-B is the distributed pressure of pile foot B, F pre-C is the distributed pressure of pile foot C, F pre-D is the distributed pressure of pile foot D; F A-real is the actual pressure at the pile foot A, F B-real is the actual pressure at the pile foot B, F C-real is the actual pressure at the pile foot C, F D-real is the actual pressure at the pile foot D; F max is the maximum pressure difference between the pile feet, F min is the minimum pressure difference between the pile feet, F ave is the average value of the maximum and minimum pressure differences between the pile feet, n' X is the distribution lifting speed of pile foot X, F X-real is the actual pressure of the pile foot X, X is the pile foot number, and X = A, B, C, D; m is the mass of the offshore wind power installation ship, and Δt is the time length of the discrete time segment in the balance control cycle.

4. The method for controlling the stability of a wind power installation vessel hoisting platform based on multi-motor different speed coordination according to claim 1 is characterized in that: The virtual drive motor No. 0 constructs the parameters of the virtual drive motor No. 0 by collecting the real-time feedback speed of the actual drive motors No. 1-12. The parameters of the virtual drive motor No. 0 include the input of the torque control current of the virtual drive motor No. 0 and the speed output of the virtual drive motor No.

0.

5. The method for stabilizing the hoisting platform of a wind power installation vessel based on multi-motor different speed coordination according to claim 1 is characterized in that: The speed unit of the speed cooperative control system includes a hybrid speed setting link, a controller of a single drive motor, a simplified inverter model, a torque mixing link, and a mathematical model of the drive motor.

6. The method for controlling the stability of a wind power installation vessel hoisting platform based on multi-motor different speed coordination according to claim 5 is characterized in that: The mixed speed includes the given speed of the electric rack and pinion lifting device, the real-time feedback speed of the current drive motor and the output speed of the No. 0 virtual drive motor.

7. The method for controlling the stability of a wind power installation vessel hoisting platform based on multi-motor different speed coordination according to claim 6 is characterized in that: The given rotation speed of the electric rack and pinion lifting device is the allocated lifting speed of the current pile foot, and the output rotation speed of the No. 0 virtual drive motor is the rotation speed output of the No. 0 virtual drive motor.

8. The method for controlling the stability of a wind power installation vessel hoisting platform based on multi-motor different speed coordination according to claim 1 is characterized in that: The feedback compensation module includes a designed feedback compensation module pile foot compensation coefficient and a designed feedback compensation module pile foot electric gear rack lifting device actual drive motor compensation coefficient.

9. The method for controlling the stability of a wind power installation vessel hoisting platform based on multi-motor different speed coordination according to claim 8 is characterized in that: The calculation of the pile foot compensation coefficient comprises the following specific steps: According to the fact that the sum of the actual pressures of the four pile feet tends to gravity and the sum of the actual moments of the four pile feet tends to zero, the minimum deviation between the sum of the actual pressures of the four pile feet and the gravity of the lifting platform is obtained; Calculate the difference between the actual pressure at the pile foot and the minimum deviation, and the compensation coefficient of the pile foot can be obtained based on the ratio of the difference to the actual pressure at the pile foot.

10. The method for controlling the stability of a wind power installation vessel hoisting platform based on multi-motor different speed coordination according to claim 8, characterized in that: The specific steps for calculating the compensation coefficient of the actual driving motor in the pile foot electric gear rack lifting device are as follows: Firstly, determine whether the number i of the failed motor in the electric rack and pinion lifting device is an even number or an odd number; secondly, stop the driving motors at the symmetrical position of the failed motor in the electric rack and pinion lifting device; finally, calculate the compensation coefficient of the actual driving motor in the pile foot electric rack and pinion lifting device according to the ratio of the driving force of the driving motor actually involved in the work and the driving force of the 12 driving motors in the lifting device.

Images