Dual self-driving permanent-magnet outer rotor hoist and synchronization control method therefor

Abstract

A dual self-driven permanent-magnet outer rotor hoist and a synchronization control method therefor, said hoist comprising: two outer rotor permanent-magnet reel assemblies, a PLC synchronization controller, and a fault-tolerant linkage device; each outer rotor permanent-magnet reel assembly comprises a left reel assembly and a right reel assembly coaxially arranged in parallel, and the left reel assembly and the right reel assembly are of a symmetrical structure; when both the left reel assembly and the right reel assembly are in a normal state, there is no rigid connection between the left reel assembly and the right reel assembly, and the PLC synchronization controller controls the left reel assembly and the right reel assembly to rotate synchronously; and when either reel assembly is in a faulty state, a rigid connection is formed between the two reel assemblies by means of the fault-tolerant linkage device, the PLC synchronization controller controls the normal reel assembly to rotate, and the normal reel assembly drives the faulty reel assembly to rotate synchronously therewith. The present invention provides a permanent-magnet-driven electric rope shovel hoist that has consumes little power and is highly reliable. The invention has the advantages of having no high-speed shaft or mechanical sliding friction pair and few transmission links, and is able to achieve flexible synchronous control operation of two motors.

Description

Dual self-driving permanent magnet outer rotor hoist and synchronous control method thereof TECHNICAL FIELD

[0001] The application belongs to the technical field of mine hoisting equipment, and in particular relates to a dual self-driving permanent magnet outer rotor hoist and a synchronous control method thereof. BACKGROUND

[0002] Steel rope hoisting systems are widely used in heavy lifting occasions in the mining, port, metallurgy and construction industries. The existing hoisting system generally uses an asynchronous motor + gear reducer to drive a winding drum to wind a steel rope for hoisting operation. The asynchronous motor often works in the low-speed zone and under the conditions of no load and under load, and has low efficiency and power factor, small torque and large power consumption. Meanwhile, the gear transmission system frequently fails in the working environment of frequent heavy load impact, and requires high maintenance.

[0003] A large-distance multi-rope traction hoisting system and a hoisting method of China University of Mining and Technology with application number 202110321942.X balance the different torques of the four main shafts corresponding to the side drums through the transmission of the transmission gears and intermediate gears between the main shafts of different direct drive units, balance the different torques of the four main shafts corresponding to the side drums through the revolution and rotation of the planetary bevel gears, and finally ensure that the driving forces output by the four drums that pull the same lifting container are equal, ensuring that the tension of each lifting rope is equal, achieving the purpose of balancing the tension of each lifting rope of the hoisting system. However, the hoisting system has too many gear transmission links, resulting in large efficiency loss.

[0004] The permanent magnet outer rotor hoist patent of Taiyuan University of Technology with application number CN201911348950.2 provides a transmission shaft-free outer rotor permanent magnet drive hoist with short-distance distributed windings and fractional slots. The permanent magnets are fixed by fixing blocks to prevent falling off, have no high-speed shaft and mechanical friction pair, have high power factor, and have small maintenance requirements.

[0005] However, the power of a single permanent magnet hoist is limited, and directly increasing the axial span of the permanent magnet drum will cause poor heat dissipation conditions inside the motor, and the long shaft motor will deform under heavy load, causing air gap magnetic field disorder and even structural damage. Moreover, the single permanent magnet self-driving outer rotor hoist still has the risk of demagnetization and falling accidents when working in a heavy load and frequent start-stop impact environment for a long time. SUMMARY

[0006] In order to solve the problems in the prior art, the application provides a double self-driving permanent magnet outer rotor hoist for a heavy load working environment and a synchronous control method thereof, realizes a high-power heavy load, low-power consumption and high-reliability permanent magnet driving hoist equipment, realizes a safe hoisting driving mode without high-speed shaft and mechanical sliding friction pair and with few transmission links, and realizes a double-machine flexible synchronous control operation method of master-slave control.

[0007] The application adopts the technical scheme as follows.

[0008] The application provides a double self-driving permanent magnet outer rotor hoist, which can be applied to a lifting device of an electric shovel and comprises a top pulley, a balance pulley, a lifting beam, a bucket, a lifting steel wire rope, a saddle, a bucket handle, a main rope, an A-shaped frame, an outer rotor permanent magnet reel assembly, a hoisting arm and a rotating platform, wherein the A-shaped frame, the outer rotor permanent magnet reel assembly and the hoisting arm are installed on the rotating platform; a top end side of the A-shaped frame is connected with one end of the main rope, and the other end of the main rope is connected with the top pulley, so that the hoisting arm is fixed by the main rope on the A-shaped frame; a crown wheel is installed at a far end of the hoisting arm from the rotating platform, and a saddle is installed at each of left and right sides of a middle part of the hoisting arm; a bucket handle is installed in each of the two saddles, and the two bucket handles are connected with the bucket; the lifting steel wire rope is wound on the outer rotor permanent magnet reel assembly, passes through the top pulley and the balance pulley and is then connected with the lifting beam, the lifting beam is connected with the bucket, and the outer rotor permanent magnet reel assembly rotates to wind or loosen the lifting steel wire rope, so as to lift or lower the bucket; and a pushing motor pushes the two bucket handles to simultaneously insert into or withdraw from the saddles.

[0009] The hoist further comprises a PLC synchronous controller and a fault-tolerant linkage device.

[0010] The outer rotor permanent magnet reel assembly comprises a first outer rotor permanent magnet reel assembly and a second outer rotor permanent magnet reel assembly, and the two outer rotor permanent magnet reel assemblies are of the same structure; each outer rotor permanent magnet reel assembly comprises coaxially and side-by-side arranged left and right reel assemblies, and the left and right reel assemblies are of a symmetrical structure.

[0011] When the left and right reel assemblies are normal, there is no rigid connection between the left and right reel assemblies, and the PLC synchronous controller controls the left and right reel assemblies to synchronously rotate; when any reel assembly is faulty, the two reel assemblies are rigidly connected through the fault-tolerant linkage device, and the PLC synchronous controller controls the normal reel assembly to rotate, and the normal reel assembly drives the faulty reel assembly to synchronously rotate.

[0012] The left winding drum assembly comprises an outer rotor, an inner stator and an encoder; the outer rotor comprises a web, a permanent magnet, a bearing and a left winding drum, the web is installed on the bearing, the permanent magnet is installed on the side of the web facing the left winding drum, and the permanent magnet is attached to the inside of the left winding drum; the inner stator comprises a main shaft support frame, a main shaft, a brake, a brake disc and a stator winding, wherein the main shaft is installed on the main shaft support frame, and the stator winding, the brake and the brake disc are installed on the main shaft; the encoder is used to collect the position signal and the speed signal of the left winding drum in real time and transmit them to the PLC synchronous controller.

[0013] The right winding drum assembly comprises an outer rotor, an inner stator and an encoder; the outer rotor comprises a web, a permanent magnet, a bearing and a right winding drum, the web is installed on the bearing, the permanent magnet is installed on the side of the web facing the right winding drum, and the permanent magnet is attached to the inside of the right winding drum; the inner stator comprises a main shaft support frame, a main shaft, a brake, a brake disc and a stator winding, wherein the main shaft is installed on the main shaft support frame, and the stator winding, the brake and the brake disc are installed on the main shaft; the encoder is used to collect the position signal and the speed signal of the right winding drum in real time and transmit them to the PLC synchronous controller.

[0014] Preferably, the inclination direction of the rope groove on the left winding drum is opposite to the inclination direction of the rope groove on the right winding drum.

[0015] Preferably, the top pulley comprises a top left pulley and a top right pulley arranged coaxially and side by side; the center axes of the top left pulley and the top right pulley are parallel to the center axes of the left winding drum and the right winding drum and perpendicular to the center axis of the balance pulley; the top left pulley is provided with a left rope groove and a right rope groove, the top right pulley is provided with a left rope groove and a right rope groove, and the balance pulley is provided with a front rope groove and a rear rope groove, wherein the rear rope groove is close to the outer rotor permanent magnet winding drum assembly; the lifting steel wire rope comprises a left lifting steel wire rope and a right lifting steel wire rope.

[0016] The left lifting steel wire rope wound on the left winding drum passes through the left rope groove of the top left pulley, the front rope groove of the balance pulley and the left rope groove of the top right pulley in sequence and is then wound on the right winding drum; the right lifting steel wire rope wound on the left winding drum passes through the right rope groove of the top left pulley, the rear rope groove of the balance pulley and the right rope groove of the top right pulley in sequence and is then wound on the right winding drum.

[0017] The balance pulley is used to control the same load of the left winding drum assembly and the right winding drum assembly.

[0018] Preferably, the left winding drum assembly is equipped with a first variable frequency driver arranged in a first variable frequency driver cabinet; the right winding drum assembly is equipped with a second variable frequency driver arranged in a second variable frequency driver cabinet; and the two variable frequency drivers are controlled by the PLC synchronous controller.

[0019] Preferably, the fault-tolerant linkage device comprises: a pair of reel gears, a fault-tolerant linkage structure; wherein the fault-tolerant linkage structure is installed on the slewing platform, one reel gear is installed on the main shaft of the left reel assembly and close to the right reel assembly, and the other reel gear is installed on the main shaft of the right reel assembly and close to the left reel assembly; the fault-tolerant linkage structure comprises: a pair of linkage sliding gears, a spline shaft, a pair of linkage yokes, a pair of linkage oil cylinders and a pair of support seats; wherein the pair of support seats are installed on the slewing platform, one linkage oil cylinder is installed on each support seat, the piston of each linkage oil cylinder is connected with one linkage yoke, each linkage yoke is connected with one linkage sliding gear, the spline shaft is installed on the two support seats, and the pair of linkage sliding gears are installed on the spline shaft and can slide on the spline shaft.

[0020] Preferably, during the movement of the lifting appliance, when both reel assemblies are normal, the linkage oil cylinders control the linkage yokes to place the linkage sliding gears at the edge positions of the two ends of the spline shaft, and lock the linkage oil cylinders, at this time, the linkage sliding gears are not engaged with the reel gears, and the two reel assemblies are not rigidly connected;

[0021] During the movement of the lifting appliance, when the encoder of any reel assembly outputs a reel fault signal to the PLC synchronous controller, the PLC synchronous controller simultaneously outputs a brake signal to the first variable frequency driver and the second variable frequency driver; under the control of the first variable frequency driver and the second variable frequency driver, the brake and the brake disc of the left reel assembly and the right reel assembly cooperate to realize braking; the PLC synchronous controller simultaneously sends a start signal to the hydraulic control systems of the two linkage oil cylinders, controls the piston to extend out of the linkage oil cylinder, and drives the linkage yoke to move the linkage sliding gear, so that the linkage sliding gear is engaged with the corresponding reel gear, thereby realizing the rigid connection between the left reel assembly and the right reel assembly; when the PLC synchronous controller simultaneously outputs a start signal to the first variable frequency driver and the second variable frequency driver, the non-fault reel assembly drives the fault reel assembly to rotate synchronously.

[0022] The application also provides a control method of the double self-driven permanent magnet outer rotor elevator, comprising:

[0023] Step 1, detecting whether the left reel assembly and the right reel assembly exist faults; if not, entering step 2, if yes, entering step 3;

[0024] Step 2, the encoder of the left winding drum assembly collects the left winding drum position signal and speed signal and transmits to the PLC synchronous controller, and the encoder of the right winding drum assembly collects the right winding drum position signal and speed signal and transmits to the PLC synchronous controller; the PLC synchronous controller obtains the synchronous control signal of the left winding drum assembly and the right winding drum assembly based on the master-slave control system; the PLC synchronous controller sends the synchronous control signal of the left winding drum assembly and the right winding drum assembly to the first variable frequency driver and the second variable frequency driver respectively, so as to synchronously control the double self-driven permanent magnet outer rotor elevator;

[0025] Step 3, the PLC synchronous controller sends the brake signal to the first variable frequency driver and the second variable frequency driver at the same time, and the PLC synchronous controller controls the meshing of the linkage sliding gear and the corresponding winding drum gear, and the non-fault winding drum assembly drives the fault winding drum assembly to rotate, so as to synchronously control the double self-driven permanent magnet outer rotor elevator.

[0026] Preferably, in step 2, the left winding drum assembly is the master motor, and the right winding drum assembly is the slave motor, the first variable frequency driver drives the master motor to rotate, and the second variable frequency driver drives the slave motor to rotate, comprising:

[0027] 1), obtaining the first position deviation amount of the current position θ1 and the target position θ of the master motor; ref

[0028] 2), obtaining the target speed ω of the master motor based on the position loop PI controller of the master motor according to the first position deviation amount; ref

[0029] 3), obtaining the first speed deviation amount Δω1 of the current speed ω1 and the target speed ω of the master motor; ref

[0030] 4), driving the master motor based on the field-oriented control / direct torque control controller of the master motor according to the first speed deviation amount Δω1;

[0031] 5), the current position θ1 of the master motor collected by the encoder of the master motor as the first input amount; the difference Δθ between the current position θ1 of the master motor collected by the encoder of the master motor and the current position θ2 of the slave motor collected by the encoder of the slave motor as the second input amount; the speed difference value obtained by the slave motor position loop PI controller through the difference Δθ as the third input amount;

[0032] 6), optimizing the parameters k of the slave motor position loop PI controller based on the neural network according to the first input amount, the second input amount and the third input amount; p i

[0033] ​​​​​7) According to the difference value Δθ, the target rotating speed ω of the slave motor is obtained based on the optimized position loop PI controller of the slave motor ref′ ;

[0034] 8) The second rotating speed deviation amount Δω2 of the current rotating speed ω2 and the target rotating speed ω of the slave motor is obtained ref′ ;

[0035] 9) According to the second rotating speed deviation amount Δω2, the slave motor is driven based on the field-oriented control / direct torque control controller of the slave motor.

[0036] Preferably, the neural network comprises an input layer, a hidden layer and an output layer; after the first input amount, the second input amount and the third input amount are transmitted from the input layer to the hidden layer, the neural network calculates the output amount of each node in the output layer; based on the current output amount of the neural network, the second rotating speed deviation amount is obtained; when the error of the second rotating speed deviation amount Δω2 and the first rotating speed deviation amount Δω1 does not exceed the limit value, the optimized position loop PI controller of the slave motor is determined according to the current output amount of the neural network; when the error of the second rotating speed deviation amount Δω2 and the first rotating speed deviation amount Δω1 exceeds the limit value, the parameters of the hidden layer and the input layer are adjusted to determine the optimized position loop PI controller of the slave motor, with the optimal gradient value of the loss function as the target.

[0037] The beneficial effects of the present application at least include that, compared with the prior art, the proposed elevator realizes safe synchronization of double machines in normal lifting work and fault working conditions through soft synchronization control and fault-tolerant linkage control. Specifically, two independent drum assemblies drive a bucket to work together without rigid connection, and cooperate with the boom pushing mechanism to complete the shovel, loading and transportation work of the electric shovel; the master-slave soft synchronization control based on neural network self-learning ensures the synchronous lifting of the double drums in normal lifting working conditions, and eliminates the influence of the position error of the two drums after the cycle lifting on the synchronization of the double motors; the fault-tolerant linkage structure is actually a kind of hydraulic control double-drum fault-tolerant linkage device, which can realize the rapid switching of the left drum and the right drum in the rigid connection and separation state (non-rigid connection), ensure that the double drum assemblies can still maintain safe synchronous rotation in the fault working condition of single drum assembly, and avoid the falling accidents of the lifting container or the lifting tool.

[0038] The application scenario of the proposed double self-driving permanent magnet outer rotor elevator is not limited to the working environment of the electric shovel, but also includes other heavy load lifting occasions in mines, metallurgy, construction and the like. BRIEF DESCRIPTION OF DRAWINGS

[0039] Fig. 1 is a structural diagram of a double self-driving permanent magnet outer rotor elevator according to the present application;

[0040] Fig. 2 is a structural diagram of the double self-driving permanent magnet outer rotor elevator applied to an electric shovel lifting device;

[0041] The reference signs in figures 1 and 2 are explained as follows: 101, top pulley; 102, balance pulley; 103, lifting beam; 104, bucket; 105, lifting wire rope; 106, saddle; 107, bucket arm; 108, main wire rope; 109, A-frame; 110, first outer rotor permanent magnet winding drum assembly; 111, lifting arm; 112, slewing platform; 113, PLC synchronous controller; 114, left variable frequency driver; 115, right variable frequency driver; 116, second outer rotor permanent magnet winding drum assembly; 117, lifting tool;

[0042] Figure 3 is a split structure schematic diagram of the outer rotor permanent magnet winding drum assembly; the outer rotor permanent magnet winding drum assembly comprises left and right winding drum assemblies arranged coaxially and side by side;

[0043] The reference signs in figure 3 are explained as follows:

[0044] 306, left winding drum; 201, web; 202, main shaft support frame; 203, main shaft; 204, brake; 205, brake disc; 206, stator winding; 207, permanent magnet; 208, bearing; 210, encoder;

[0045] Figure 4 is a working schematic diagram of the lifting system of the lifting machine in the present application;

[0046] The reference signs in figure 4 are explained as follows:

[0047] 301, top left pulley; 302, top right pulley; 102, balance pulley; 304, left side lifting wire rope 1; 305, right side lifting wire rope 2; 306, left winding drum; 307, right winding drum;

[0048] Figure 5 is a structure principle diagram of the master-slave control system in the embodiment of the present application;

[0049] Figure 6 is a soft synchronization control block diagram of the left and right winding drum assemblies in the embodiment of the present application;

[0050] Figure 7 is a structure schematic diagram of the double winding drum fault-tolerant linkage system of the lifting machine in the present application;

[0051] The reference signs in figure 7 are explained as follows:

[0052] 601, winding drum gear; 602, linkage sliding gear; 603, spline shaft; 604, linkage shift fork; 605, linkage oil cylinder; 606, support seat;

[0053] Figure 8 is a control method flow chart of the double self-driven outer rotor permanent magnet lifting machine in the present application. DETAILED DESCRIPTION

[0054] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present application. The embodiments described in the present application are only a part of the embodiments of the present application, rather than all the embodiments. All other embodiments obtained by those skilled in the art without creative efforts based on the spirit of the present application shall fall within the protection scope of the present application.

[0055] The present application provides a double self-driving permanent magnet outer rotor hoist, which is used in heavy load lifting occasions in mining, port, metallurgy and construction industries; as shown in FIGS. 1 and 2, the hoist comprises a top pulley 101, a balance pulley 102, a lifting beam 103, a bucket 104, a lifting steel wire rope 105, a saddle 106, a bucket handle 107, a main rope 108, an A-shaped frame 109, a first outer rotor permanent magnet drum assembly 110, a hoisting arm 111, a rotating platform 112, a PLC synchronous controller 113, a left variable frequency driver 114, a right variable frequency driver 115, a second outer rotor permanent magnet drum assembly 116, and a lifting tool 117. The first outer rotor permanent magnet drum assembly and the second outer rotor permanent magnet drum assembly are installed on the rotating platform, the top pulley comprises a pair of symmetrical pulleys, the winding method is as shown in FIG. 3, the two ends of the lifting steel wire rope are connected with the first outer rotor permanent magnet drum assembly and the second outer rotor permanent magnet drum assembly respectively and pass through the top pulley, and the middle part passes through the balance pulley on the lifting tool, so that the loads borne by the first outer rotor permanent magnet drum assembly and the second outer rotor permanent magnet drum assembly are balanced and equal.

[0056] Among them, the A-shaped frame, the first outer rotor permanent magnet drum assembly, the second outer rotor permanent magnet drum assembly and the hoisting arm are installed on the rotating platform; the top end of the A-shaped frame is connected with one end of the main rope, and the other end of the main rope is connected with the top pulley, so as to realize that the hoisting arm is fixed by the main rope on the A-shaped frame; the end of the hoisting arm away from the rotating platform is installed with the top pulley, and the left and right sides of the middle part of the hoisting arm are respectively installed with one saddle, one bucket handle is installed in each saddle, and the two bucket handles are connected with the bucket; the first outer rotor permanent magnet drum assembly and the second outer rotor permanent magnet drum assembly are both wound with the lifting steel wire rope, the lifting steel wire rope is connected with the lifting beam after passing through the top pulley and the balance pulley, the lifting beam is connected with the bucket, the outer rotor permanent magnet drum assembly lifts or lowers the bucket by winding the lifting steel wire rope, the pushing motor pushes the two bucket handles to insert or withdraw from the saddle at the same time, and the digging work of the electric shovel is completed by cooperative operation.

[0057] Specifically, the first outer rotor permanent magnet winding assembly and the second outer rotor permanent magnet winding assembly are structurally identical, each outer rotor permanent magnet winding assembly comprises coaxially arranged left winding assembly and right winding assembly, the left winding assembly and the right winding assembly are symmetrical structures, there is no rigid connection between the left winding assembly and the right winding assembly when both the left winding assembly and the right winding assembly are normal, and the left winding assembly and the right winding assembly are in a separated state; as shown in FIG. 3, the left winding assembly comprises an outer rotor, an inner stator and an encoder 210; the outer rotor comprises a web plate 201, a permanent magnet 207, a bearing 208 and a left winding 306, the web plate is installed on the bearing, the permanent magnet is installed on the side of the web plate facing the left winding, and the permanent magnet is attached to the inside of the left winding; the inner stator comprises a main shaft support frame 202, a main shaft 203, a brake 204, a brake disc 205 and a stator winding 206, wherein the main shaft is installed on the main shaft support frame, and the stator winding, the brake and the brake disc are installed on the main shaft; the outer rotor and the inner stator jointly form an outer rotor permanent magnet synchronous motor with a brake function; the encoder is used to collect position signals and speed signals of the left winding in real time and transmit the signals to a PLC synchronous controller.

[0058] Similarly, as shown in FIGS. 3 and 4, the right winding assembly comprises an outer rotor, an inner stator and an encoder; the outer rotor comprises a web plate, a permanent magnet, a bearing and a right winding 307, the web plate is installed on the bearing, the permanent magnet is installed on the side of the web plate facing the right winding, and the permanent magnet is attached to the inside of the right winding; the inner stator comprises a main shaft support frame, a main shaft, a brake, a brake disc and a stator winding, wherein the main shaft is installed on the main shaft support frame, and the stator winding, the brake and the brake disc are installed on the main shaft; the outer rotor and the inner stator jointly form an outer rotor permanent magnet synchronous motor with a brake function; the encoder is used to collect position signals and speed signals of the right winding in real time and transmit the signals to a PLC synchronous controller.

[0059] Further, the inclination direction of the rope groove on the left winding is opposite to the inclination direction of the rope groove on the right winding. As shown in FIG. 3, the left winding and the right winding are placed side by side, and the rope groove bias angles on them are both inward, the traditional gear transmission system is removed, the transmission efficiency is improved, the reliability of the transmission system is improved, and the maintenance workload is reduced. In the case where space is not allowed, the two windings can be arranged in front of and behind each other or staggered.

[0060] The lifting machine adopts the left drum assembly and the right drum assembly to form the outer rotor permanent magnet driving drum assembly, the left drum assembly and the right drum assembly are used as the driving motor of the electric shovel lifting system, compared with the long-span single permanent magnet drum lifting device with high length-diameter ratio and two end supports, the axial span of the left drum assembly and the right drum assembly is short and has an independent supporting structure, so that the stress condition is good, and unacceptable distortion and motor air gap disorder are not caused by high length-diameter ratio and large span.

[0061] The lifting system in the lifting machine comprises a top pulley, a balance pulley, a lifting steel wire rope and an outer rotor permanent magnet drum assembly.

[0062] Specifically, as shown in FIG. 4, the top pulley comprises a top left pulley 301 and a top right pulley 302 arranged coaxially and side by side; the center shafts of the top left pulley and the top right pulley are parallel to the center shafts of the left drum and the right drum, and are perpendicular to the center shaft of the balance pulley. The top left pulley is provided with left and right rope grooves, the top right pulley is provided with left and right rope grooves, and the balance pulley is provided with front and rear rope grooves, wherein the rear rope groove is close to the outer rotor permanent magnet drum assembly. The lifting steel wire rope comprises a left side lifting steel wire rope 304 and a right side lifting steel wire rope 305. The left side lifting steel wire rope wound on the left drum passes through the left side rope groove of the top left pulley, the front rope groove of the balance pulley and the left rope groove of the top right pulley in sequence, and is then wound on the right drum; the right side lifting steel wire rope wound on the left drum passes through the right rope groove of the top left pulley, the rear rope groove of the balance pulley and the right rope groove of the top right pulley in sequence, and is then wound on the right drum. The winding mode of the lifting system has two steel wire ropes in total, which are wound in the four rope grooves of the top left pulley and the top right pulley from the balance pulley, and then are fixed on the inside of the drum. The rope grooves on the two drums are inclined to the direction of the lifting arm, the balance pulley is used to balance the tension of the two side lifting steel wire ropes, the left drum winds the left ends of the two steel wire ropes, and the right drum winds the right ends of the two steel wire ropes.

[0063] The left drum assembly is equipped with a first variable frequency driver arranged in a first variable frequency driver cabinet; the right drum assembly is equipped with a second variable frequency driver arranged in a second variable frequency driver cabinet; and the two variable frequency drivers are controlled by a PLC synchronous controller.

[0064] In the non-restrictive preferred embodiment, the motor parameters of the left drum assembly and the right drum assembly are the same, the winding phase is the same, and thus the driving torque, the load torque and the friction torque are also the same, satisfying the following relationship:

[0065] In the formula, T e is the driving torque, T L is the load torque, T f is the friction torque, J is the moment of inertia, is the winding phase.

[0066] The left drum assembly and the right drum assembly can basically move synchronously under open-loop synchronization, but due to differences in manufacturing and assembly precision, load fluctuations, environmental factors and the like, it is inevitable to cause asynchrony between the double shafts of the left drum assembly and the right drum assembly, especially in the lifting mechanism of the electric shovel, the frequent lifting and lowering cycles will accumulate position errors, and thus the errors of the speed and the position need to be controlled.

[0067] The soft synchronization control flow is shown in FIG. 5, including: a balance pulley for controlling the same load of the left drum assembly and the right drum assembly, an encoder of the left drum assembly transmitting a position signal and a speed signal of the left drum assembly to a PLC synchronization controller, and simultaneously an encoder of the right drum assembly transmitting a position signal and a speed signal of the right drum assembly to the PLC synchronization controller; the PLC synchronization controller simultaneously sending a control signal to a first variable frequency driver and a second variable frequency driver; in the non-restrictive preferred embodiment, taking the left drum assembly as the master motor and the right drum assembly as the slave motor, the first variable frequency driver drives the master motor to rotate, and simultaneously the second variable frequency driver drives the slave motor to rotate.

[0068] The PLC synchronization controller includes a master-slave control system, and the soft synchronization control is realized based on the master-slave control system, and in the non-restrictive preferred embodiment, the soft synchronization control of the left drum assembly and the right drum assembly is shown in FIG. 6, including:

[0069] 1) obtaining a first position deviation amount of a current position θ1 of the master motor and a target position θ ref of the master motor;

[0070] 2) obtaining a target speed ω ref of the master motor based on a position loop PI controller of the master motor according to the first position deviation amount;

[0071] 3) obtaining a first speed deviation amount Δω1 of a current speed ω1 of the master motor and a target speed ω ref of the master motor;

[0072] 4) driving the master motor PMSM1 based on a FOC / DTC (field oriented control / direct torque control) controller of the master motor according to the first speed deviation amount Δω1.

[0073] 5) The current position θ1 of the main motor acquired by the encoder of the main motor in real time as the first input quantity; the difference Δθ between the current position θ1 of the main motor acquired by the encoder of the main motor in real time and the current position θ2 of the slave motor acquired by the encoder of the slave motor as the second input quantity; the speed difference value obtained by the difference Δθ through the slave motor position loop PI controller as the third input quantity;

[0074] 7) According to the first input quantity, the second input quantity and the third input quantity, the parameters k of the slave motor position loop PI controller are optimized based on the neural network p , k i ;

[0075] 7) According to the difference Δθ, the target speed ω of the slave motor is obtained based on the optimized position loop PI controller of the slave motor ref′ ;

[0076] 8) The second speed deviation Δω2 of the current speed ω2 and the target speed ω of the slave motor ref′ ;

[0077] 9) According to the second speed deviation Δω2, the FOC / DTC (field oriented control / direct torque control) controller of the slave motor PMSM2 is based on to drive the slave motor.

[0078] Further, the neural network includes an input layer, a hidden layer and an output layer; after the first input quantity, the second input quantity and the third input quantity are transmitted from the input layer to the hidden layer, the neural network calculates the output quantity of each node in the output layer; based on the current output quantity of the neural network, the second speed deviation is obtained; when the error of the second speed deviation Δω2 and the first speed deviation Δω1 does not exceed the limit value, the optimized position loop PI controller of the slave motor is determined by the current output quantity of the neural network; when the error of the second speed deviation Δω2 and the first speed deviation Δω1 exceeds the limit value, the parameters of the hidden layer and the input layer are adjusted to determine the optimized position loop PI controller of the slave motor, with the optimal gradient value of the loss function as the target; in the non-restrictive preferred embodiment, the first speed deviation Δω1 and the second speed deviation Δω2 are equal to the speed deviation Δω, and the preferred value of the limit value is 0.

[0079] The master-slave control system proposed in the application realizes the master-slave position soft synchronous control with adaptive ability, under the condition that the load of the left drum assembly and the right drum assembly is balanced by the balance pulley, not only can ensure that the speed of the left drum assembly and the right drum assembly is the same, to improve the stability of the bucket movement by the synchronous movement of the double shaft, but also can adaptively release the accumulated position error in the lifting and lowering cycle.

[0080] The synchronous control is realized under the premise that the left drum assembly and the right drum assembly are normal, and when any drum assembly appears a fault such as a loss of excitation, the shovel bucket will fall due to a harsh working environment of the electric shovel, so a fault-tolerant linkage control of the double drum assemblies is needed to avoid the expansion of the accident, therefore, as shown in Figure 7, the elevator provided by the present application further comprises a fault-tolerant linkage device, the fault-tolerant linkage device comprises: a pair of drum gears 601 and a fault-tolerant linkage structure, wherein the fault-tolerant linkage structure is installed on the slewing platform, one drum gear is installed on the main shaft of the left drum assembly and close to the right drum assembly, and the other drum gear is installed on the main shaft of the right drum assembly and close to the left drum assembly; the fault-tolerant linkage structure comprises: a pair of linkage sliding gears 602, a spline shaft 603, a pair of linkage yokes 604, a pair of linkage oil cylinders 605 and a pair of support seats 606, wherein the pair of support seats are installed on the slewing platform, one linkage oil cylinder is installed on each support seat, the piston of each linkage oil cylinder is connected with one linkage yoke, each linkage yoke is connected with one linkage sliding gear, the spline shaft is installed on the two support seats and can slide on the spline shaft.

[0081] During the movement of the shovel bucket, when both drum assemblies are normal, the linkage oil cylinders control the linkage yokes to place the linkage sliding gears on the edge positions of the two ends of the spline shaft, and the linkage oil cylinders are locked, at this time, the linkage sliding gears are not engaged with the drum gears, and the two drum assemblies are not rigidly connected and can independently operate;

[0082] During the movement of the shovel bucket, when the encoder of any drum assembly outputs a drum fault signal to the PLC synchronous controller, the PLC synchronous controller simultaneously outputs a brake signal to the first variable frequency driver and the second variable frequency driver; under the control of the first variable frequency driver and the second variable frequency driver, the brakes and the brake discs of the left drum assembly and the right drum assembly cooperate to realize braking; the PLC synchronous controller simultaneously sends a start signal to the hydraulic control systems of the two linkage oil cylinders to control the pistons to extend out of the linkage oil cylinders, the pistons drive the linkage yokes to move the linkage sliding gears, so that the linkage sliding gears are engaged with the corresponding drum gears, thereby realizing the rigid connection between the left drum assembly and the right drum assembly; when the PLC synchronous controller simultaneously outputs a start signal to the first variable frequency driver and the second variable frequency driver, the non-fault drum assembly drives the fault drum assembly to rotate synchronously, realizing the synchronous rotation of the two drum assemblies, safely completing the current lowering operation, and avoiding the occurrence of the shovel bucket falling accident.

[0083] In the lifting machine, the components that must rotate synchronously in the two drum assemblies include the web, the brake disc, the permanent magnet, the left drum and the right drum; permanent magnets are attached to the inner walls of the left drum and the right drum, and the electromagnetic characteristics of the permanent magnets when rotating are used as the criterion for determining whether the two drum assemblies rotate synchronously; the permanent magnets are radially magnetized, the stator winding is installed on the core of the main shaft, the power line is connected to the stator winding through the hole in the main shaft to provide current to the left drum assembly and the right drum assembly, the square shafts at the two ends of the main shaft are installed on the main shaft support frame to limit the rotation of the main shaft, and the left drum assembly and the right drum assembly are supported by bearings between the web and the main shaft and rotate under the action of the rotating magnetic field formed by the stator winding. The left drum assembly and the right drum assembly can be started smoothly at ultra-low frequency, operate at low speed and high torque, and have high motor efficiency.

[0084] In the lifting machine, soft synchronization control and fault-tolerant linkage control are used to realize the safe synchronization of the two machines under normal digging and fault conditions. Specifically, two independent drum assemblies drive a bucket to work together without rigid connection, and the bucket rod pressing mechanism cooperates to complete the digging, loading and transporting operations of the electric shovel; the master-slave soft synchronization control based on neural network self-learning ensures the synchronous lifting of the two drums under normal digging conditions, and eliminates the influence of the position error of the two drums after the cyclic lifting on the synchronization of the two motors; the fault-tolerant linkage structure is actually a hydraulic control double-drum fault-tolerant linkage device, which can realize the rapid switching of the left drum and the right drum under the conditions of rigid connection and separation (non-rigid connection), ensure that the double-drum assembly can still maintain safe synchronous rotation under single-drum assembly fault conditions, and avoid bucket falling accidents.

[0085] The lifting machine has no transmission shaft and mechanical sliding friction pair, has the advantages of high power factor, good starting characteristics, simple manufacturing process, easy assembly and the like.

[0086] The application further provides a synchronization control method of the double self-driven permanent magnet outer rotor lifting machine, as shown in Fig. 8, which comprises the following steps:

[0087] Step 1, detecting whether the left drum assembly and the right drum assembly have faults; if not, entering step 2, if yes, entering step 3;

[0088] Specifically, when the PLC synchronization controller performs synchronization control on the left drum assembly and the right drum assembly based on the master-slave control system, the rotation speed signals and the current signals of the left drum assembly and the right drum assembly are collected to detect whether the left drum assembly and the right drum assembly have faults.

[0089] Step 2, the encoder of the left winding drum assembly collects the left winding drum position signal and speed signal and transmits to the PLC synchronous controller, and the encoder of the right winding drum assembly collects the right winding drum position signal and speed signal and transmits to the PLC synchronous controller; the PLC synchronous controller obtains the synchronous control signals of the left winding drum assembly and the right winding drum assembly based on the master-slave control system; the PLC synchronous controller sends the synchronous control signals of the left winding drum assembly and the right winding drum assembly to the first variable frequency driver and the second variable frequency driver respectively, so as to synchronously control the double self-driven permanent magnet outer rotor elevator;

[0090] Step 3, the PLC synchronous controller sends the brake signal to the first variable frequency driver and the second variable frequency driver at the same time, and the PLC synchronous controller controls the meshing of the linkage sliding gear and the corresponding winding drum gear, and the non-fault winding drum assembly drives the fault winding drum assembly to rotate, so as to synchronously control the double self-driven permanent magnet outer rotor elevator.

[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application and not to limit it, although the present application has been described in detail with reference to the above embodiments, those skilled in the art should understand that the specific embodiments of the present application can be modified or replaced by the equivalent, without departing from the spirit and scope of the present application, any modification or equivalent replacement should be covered in the protection scope of the claims of the present application.

Claims

1. A synchronous control method of a dual self-driven permanent magnet outer rotor elevator, characterized by, Comprise: The double self-driven permanent magnet outer rotor hoist comprises an outer rotor permanent magnet drum assembly, a PLC synchronous controller and a fault-tolerant linkage device. The outer rotor permanent magnet drum assembly comprises a first outer rotor permanent magnet drum assembly and a second outer rotor permanent magnet drum assembly. The two outer rotor permanent magnet drum assemblies are structurally identical. Each outer rotor permanent magnet drum assembly comprises coaxially arranged left drum assembly and right drum assembly. The left drum assembly and the right drum assembly are symmetrically structured. The left drum assembly and the right drum assembly each comprise an encoder. The left drum assembly is equipped with a first variable frequency driver. The right drum assembly is equipped with a second variable frequency driver. The two variable frequency drivers are controlled by the PLC synchronous controller. When the left drum assembly and the right drum assembly are normal, there is no rigid connection between the left drum assembly and the right drum assembly. The PLC synchronous controller controls the synchronous rotation of the left drum assembly and the right drum assembly. When any one of the drum assemblies fails, the two drum assemblies are rigidly connected through the fault-tolerant linkage device. The PLC synchronous controller controls the rotation of the normal drum assembly, and the normal drum assembly drives the synchronous rotation of the failed drum assembly. The fault-tolerant linkage device comprises a pair of drum gears and a fault-tolerant linkage structure. The fault-tolerant linkage structure is installed on the rotating platform. One drum gear is installed on the main shaft of the left drum assembly and close to the right drum assembly. The other drum gear is installed on the main shaft of the right drum assembly and close to the left drum assembly. The fault-tolerant linkage structure comprises a pair of linkage sliding gears, a spline shaft, a pair of linkage yokes, a pair of linkage oil cylinders and a pair of support seats. The pair of support seats are installed on the rotating platform. Each support seat is installed with a linkage oil cylinder. The piston of each linkage oil cylinder is connected with a linkage yoke. Each linkage yoke is connected with a linkage sliding gear. The spline shaft is installed on the two support seats and can slide on the spline shaft. The pair of linkage sliding gears are installed on the spline shaft and can slide on the spline shaft. Step 1, detect whether the left drum assembly and the right drum assembly exist faults; if not, go to step 2, if yes, go to step 3; Step 2, the encoder of the left drum assembly collects the left drum position signal and speed signal in real time and transmits them to the PLC synchronous controller. The encoder of the right drum assembly collects the right drum position signal and speed signal in real time and transmits them to the PLC synchronous controller. The PLC synchronous controller obtains the synchronous control signal of the left drum assembly and the right drum assembly based on the master-slave control system. The PLC synchronous controller sends the synchronous control signal of the left drum assembly and the right drum assembly to the first variable frequency driver and the second variable frequency driver respectively to synchronously control the double self-driven permanent magnet outer rotor hoist. In step 2, the left drum assembly is the master motor and the right drum assembly is the slave motor. The first variable frequency driver drives the master motor to rotate, and the second variable frequency driver drives the slave motor to rotate, comprising: 1) obtain the first position deviation amount of the current position θ1 and the target position θ of the main motor ref of the main motor; 2) According to the first position deviation, the target speed of the main motor ω is obtained based on the position loop PI controller of the main motor ref ; 3) obtain the current rotating speed ω1 of the main motor and the target rotating speed ω ref of the first rotating speed deviation Δω1; 4) According to the first speed deviation Δω1, based on the field-oriented control / direct torque control controller of the master motor, to drive the master motor; 5), the current position θ1 of the main motor collected by the encoder of the main motor in real time as the first input quantity; the difference Δθ between the current position θ1 of the main motor collected by the encoder of the main motor in real time and the current position θ2 of the slave motor collected by the encoder of the slave motor as the second input quantity; the speed difference value obtained by the difference Δθ through the position loop PI controller of the slave motor as the third input quantity; 6) Optimizing the parameter k from the motor position loop PI controller based on neural network, according to the first input quantity, the second input quantity and the third input quantity p , k i ; 7) Based on the difference Δθ, the target speed ω of the slave motor is obtained from the optimized position loop PI controller of the slave motor ref′ ; 8), a second rotational speed deviation amount Δω2 is obtained from the current rotational speed ω2 of the motor and the target rotational speed ω ref′ of the motor 9), based on the second speed deviation Δω2, the field-oriented control / direct torque control controller of the slave motor is controlled to drive the slave motor; Step 3, the PLC synchronous controller sends a brake signal to the first variable frequency driver and the second variable frequency driver at the same time, and the PLC synchronous controller controls the engagement of the linkage sliding gear and the corresponding drum gear, and the non-fault drum assembly drives the fault drum assembly to rotate, so as to synchronously control the double self-driving permanent magnet outer rotor hoist.

2. The synchronous control method of the double self-driving permanent magnet outer rotor hoist according to claim 1, characterized in that, The neural network includes an input layer, a hidden layer and an output layer; the first input quantity, the second input quantity and the third input quantity are transmitted from the input layer to the hidden layer, and the neural network calculates the output quantity of each node in the output layer; based on the current output quantity of the neural network, the second speed deviation Δω2 is obtained; when the error between the second speed deviation Δω2 and the first speed deviation Δω1 does not exceed the limit value, the optimized position loop PI controller of the slave motor is determined according to the current output quantity of the neural network; when the error between the second speed deviation Δω2 and the first speed deviation Δω1 exceeds the limit value, the optimized position loop PI controller of the slave motor is determined by taking the optimal gradient value of the loss function as the target to adjust the parameters of the hidden layer and the input layer.

3. A double self-driven permanent magnet outer rotor elevator which hoists a shovel by using the control method according to claim 1 or 2, characterized by It comprises: The top pulley, the balance pulley, the lifting beam, the bucket, the lifting steel wire rope, the saddle, the bucket handle, the main rope, the A-shaped frame, the outer rotor permanent magnet drum assembly, the lifting arm, and the rotating platform are installed on the rotating platform. The top end of the A-shaped frame is connected to one end of the main rope, and the other end of the main rope is connected to the top pulley, so that the lifting arm is fixed by the main rope on the A-shaped frame. The end of the lifting arm away from the rotating platform is installed with the top pulley, and the left and right sides of the middle part of the lifting arm are respectively installed with one saddle. Each saddle is installed with one bucket handle, and the two bucket handles are connected to the bucket. The lifting steel wire rope is wound on the outer rotor permanent magnet drum assembly, and the lifting steel wire rope is connected to the lifting beam after passing through the top pulley and the balance pulley. The lifting beam is connected to the bucket. The outer rotor permanent magnet drum assembly rotates to wind or loosen the lifting steel wire rope, so as to lift or lower the bucket. The pushing motor pushes the two bucket handles to simultaneously insert or withdraw from the saddle.

4. The double self-driving permanent magnet outer rotor hoist according to claim 3, characterized in that, The left drum assembly comprises an outer rotor and an inner stator. The outer rotor comprises a web plate, a permanent magnet, a bearing and a left drum. The web plate is installed on the bearing, and the permanent magnet is installed on the side of the web plate facing the left drum. The inner stator comprises a main shaft support frame, a main shaft, a brake, a brake disc and a stator winding. The main shaft is installed on the main shaft support frame, and the main shaft is provided with the stator winding, the brake and the brake disc. The right winding drum assembly comprises an outer rotor and an inner stator, the outer rotor comprises a web plate, a permanent magnet, a bearing and a right winding drum, the web plate is installed on the bearing, the permanent magnet is installed on the side of the web plate facing the right winding drum, and the permanent magnet is attached to the inside of the right winding drum; the inner stator comprises a main shaft support frame, a main shaft, a brake, a brake disc and a stator winding, wherein the main shaft is installed on the main shaft support frame, and the stator winding, the brake and the brake disc are installed on the main shaft.

5. The double self-driven permanent magnet outer rotor hoist according to claim 4, wherein, The inclination direction of the rope groove on the left winding drum is opposite to the inclination direction of the rope groove on the right winding drum.

6. The double self-driven permanent magnet outer rotor hoist according to claim 5, wherein, The top pulley comprises a top left pulley and a top right pulley arranged coaxially and side by side, the center shafts of the top left pulley and the top right pulley are parallel to the center shafts of the left winding drum and the right winding drum and perpendicular to the center shaft of the balance pulley, the top left pulley is provided with a left rope groove and a right rope groove, the top right pulley is provided with a left rope groove and a right rope groove, and the balance pulley is provided with a front rope groove and a rear rope groove, wherein the rear rope groove is close to the permanent magnet winding drum assembly of the outer rotor; the lifting steel wire rope comprises a left lifting steel wire rope and a right lifting steel wire rope; The left lifting steel wire rope wound on the left winding drum passes through the left rope groove of the top left pulley, the front rope groove of the balance pulley and the left rope groove of the top right pulley in sequence and is then wound on the right winding drum; the right lifting steel wire rope wound on the left winding drum passes through the right rope groove of the top left pulley, the rear rope groove of the balance pulley and the right rope groove of the top right pulley in sequence and is then wound on the right winding drum; The balance pulley is used to control the same load of the left winding drum assembly and the right winding drum assembly.

7. The double self-driven permanent magnet outer rotor hoist according to claim 4, wherein, The first variable frequency driver is arranged in the first variable frequency driver cabinet, and the second variable frequency driver is arranged in the second variable frequency driver cabinet.

8. The double self-driven permanent magnet outer rotor hoist according to claim 3, wherein, During the movement of the lifting tool, when both winding drum assemblies are normal, the linkage oil cylinder controls the linkage shift gear to be located at the edge positions of the two ends of the spline shaft, and the linkage oil cylinder is locked, at this time, the linkage shift gear is not engaged with the winding drum gear, and the two winding drum assemblies are not rigidly connected. When the encoder of any drum assembly outputs a drum fault signal to the PLC synchronous controller during the movement of the sling, the PLC synchronous controller simultaneously outputs a brake signal to the first variable frequency driver and the second variable frequency driver; under the control of the first variable frequency driver and the second variable frequency driver, the brake and the brake disc of the left drum assembly and the right drum assembly cooperate to realize braking; the PLC synchronous controller simultaneously sends a start signal to the hydraulic control system of the two linkage oil cylinders, controls the piston to extend from the linkage oil cylinder, and drives the linkage yoke to move the linkage sliding gear, so that the linkage sliding gear is engaged with the corresponding drum gear, thereby realizing the rigid connection between the left drum assembly and the right drum assembly; when the PLC synchronous controller simultaneously outputs a start signal to the first variable frequency driver and the second variable frequency driver, the non-fault drum assembly drives the fault drum assembly to rotate synchronously.

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