A control method for constant / super-torque starting and running of a mechatronic planetary speed regulating device

Abstract

The present application relates to the field of high-power speed regulation, in particular to a control method for constant / super-torque starting and running of a mechanical-electrical integrated planetary speed regulation device, which is suitable for the field of industrial drive speed regulation, and especially suitable for driving devices such as compressors in petrochemical and natural gas industries.In the starting process, the load is proportionally shared by the speed regulation motor and the main drive motor, and according to the capacity of the two-quadrant frequency converter configured for the main drive motor, the output torque of the sun gear can be kept constant, rated, or even exceed the rated torque.The main drive motor and the speed regulation motor keep the constant torque mode, so that the output of the device also keeps the constant torque mode.Under normal circumstances, the torque of pumps and fans is in a quadratic relationship with the speed, and the torque of compressors in petrochemical industries is between a linear relationship and a quadratic relationship with the speed, both of which are less than the constant torque mode, so that the starting and running requirements can be met.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high-power speed regulation, in particular to a control method for constant / super-torque starting and running of a mechatronic planetary speed regulation device, which is suitable for industrial drive speed regulation field, and is especially suitable for driving equipment such as compressors in petrochemical and natural gas industries. BACKGROUND

[0002] As the highest efficiency high-power speed regulation device at present, the mechatronic planetary speed regulation device (hereinafter referred to as device) has attracted high attention in related industries. The device has been applied to the speed regulation of electric feed water pumps in thermal power plants, and the petrochemical industry has also begun to study the replacement of electric energy to improve the electrification rate and use as much “green electricity” as possible to achieve the goal of carbon reduction and environmental protection. Specifically, the motor drive is used to replace the small steam turbine drive, and the compressors in the petrochemical industry, especially the ethylene three-machine, have very high reliability requirements, and the starting torque is very large, which may even exceed the rated torque during pressure starting. The motor starting is difficult. There are three kinds of motor drive speed regulation methods currently being researched or already adopted. One is to use a planetary hydraulic speed regulation device with a hydraulic coupling for soft starting, and the motor is started under no-load voltage reduction. The second is to use a motor with a full-capacity frequency converter for starting and speed regulation. The third is to use a mechatronic planetary speed regulation device. Among them, the torque characteristic of the planetary hydraulic speed regulation device is reduced at low speed, which is not conducive to the starting of the compressor under large torque and super-torque conditions, and the selection needs to be increased. When the full-capacity frequency conversion method encounters super-rated torque starting, both the motor and the frequency converter are overloaded, and the selection capacity of the motor and the frequency converter also needs to consider this factor, so the selection capacity will increase, and the industry is also more worried about the reliability of the long-period safe operation of the high-power frequency converter. SUMMARY

[0003] The application number 202110958640.3 and the invention name of a mechatronic planetary speed regulation device for full-range speed regulation propose two ways of mechanical soft starting and frequency conversion soft starting of the device. The present application proposes a control method for constant torque or super-rated torque starting and running of a mechatronic planetary speed regulation device based on the combination of mechanical soft starting and frequency conversion soft starting.

[0004] The application is implemented by the following technical scheme: a control method for constant / super-torque starting and running of a mechatronic planetary speed regulating device, wherein the mechatronic planetary speed regulating device comprises a main drive motor, a main drive end gear, a differential planetary mechanism (a sun gear, a planet gear, an inner ring gear, and a planet carrier are connected in a planetary gear box mode), a speed regulating end idler, a speed regulating end gear, a synchronous automatic clutch, a clutch output end gear, a clutch output end idler, a speed regulating motor, a four-quadrant frequency converter (containing an incoming line switch and a transformer), a two-quadrant frequency converter (containing an incoming line switch and a transformer, used for soft starting of the main drive motor), a bypass switch, a plant power supply system, a speed regulating motor switch, and a main drive motor switch; the inner ring gear input shaft of the differential planetary mechanism is connected with the main drive end gear; the main drive end gear is connected with the clutch output end idler and the clutch output end gear; the clutch output end gear is connected with the output shaft of the synchronous automatic clutch; the main drive motor is connected with the main drive end gear; the planet carrier of the differential planetary mechanism is connected with the speed regulating end idler; the speed regulating end idler is engaged with the speed regulating end gear; the speed regulating end gear is connected with the speed regulating motor; the speed regulating end idler is connected with the input shaft of the synchronous automatic clutch; one end of the four-quadrant frequency converter is connected with the plant power supply system, and the other end is connected with the speed regulating motor through the speed regulating motor switch; one end of the two-quadrant frequency converter is connected with the plant power supply system, and the other end is connected with the main drive motor through the main drive motor switch; the main drive motor is also directly connected with the plant power supply system through the bypass switch; and the sun gear of the differential planetary mechanism is connected with a driven device.

[0005] The specific process of the control method for constant / super-torque starting and running is as follows: when the device starts, the two-quadrant frequency converter and the four-quadrant frequency converter start at the same time; the two-quadrant frequency converter drives the main drive motor to start at a variable frequency, the main drive motor drives the inner ring gear to increase in speed, thereby driving the sun gear to increase in speed; during the speed increasing process, the sun gear is subjected to the resistance torque of the driven device, the planet carrier is subjected to a reverse torque (in the reverse direction) to increase in speed, and the speed regulating end idler is driven to increase in speed; the four-quadrant frequency converter drives the speed regulating motor to actively (in the reverse direction) increase in speed, thereby driving the speed regulating end idler to increase in speed; the main drive end gear increases in speed along with the main drive motor, thereby driving the clutch output end idler and the clutch output end gear to increase in speed; due to the action of the resistance torque of the speed regulating motor and the driven device, the speed regulating end idler continuously increases in speed until the synchronous automatic clutch connected with the idler is engaged; at this time, the main drive motor and the speed regulating motor jointly drive the device to increase in speed, that is, the inner ring gear, the planet carrier, and the sun gear synchronously increase in speed, the sun gear drives the driven device to increase in speed, and when the frequency of the main drive motor increases to the working frequency, the speed regulating motor also reaches the highest reverse speed; the main drive motor is cut to the working frequency, and the starting process of the device is completed (the starting process of the driven device is synchronously completed, or the device further increases in speed to complete the starting process of the driven device).

[0006] In the starting process, the speed-regulating motor and the main drive motor share the load in proportion. According to the two-quadrant frequency converter capacity configured for the main drive motor, the sun gear output torque can be kept constant torque, rated torque, or even exceed the rated torque, and the main drive motor and the speed-regulating motor do not have to be oversized, but can be kept at the rated power.

[0007] The main drive motor and the speed-regulating motor keep the constant torque mode, and the device output also keeps the constant torque mode. Generally, the torque of the pump and the fan is in a quadratic relationship with the speed, and the torque of the compressor in the petrochemical industry is between the first power and the second power, both of which are less than the constant torque mode, so the starting and running requirements can be met.

[0008] In the starting process, the main drive motor and the speed-regulating motor work in the electric mode through the control of the two-quadrant frequency converter and the four-quadrant frequency converter, and jointly bear the load. After the synchronous automatic clutch is engaged, the differential planetary mechanism becomes a constant speed ratio gear box. The stator synchronous speed of the speed-regulating motor (asynchronous motor, synchronous motor is a motor power angle) must be controlled to be higher than the rotor speed to form the slip rate, so that the speed-regulating motor works in the electric mode, and the synchronous automatic clutch always maintains the overrunning torque, so that the synchronous automatic clutch is stably engaged. The power (torque) of the speed-regulating motor and the power (torque) of the main drive motor converge at the main drive end gear to drive the driven equipment. Since the planetary carrier is in a reverse rotation state, a circulating power closed loop is also formed between the planetary carrier and the inner ring gear. Without considering the efficiency loss, the input power of the inner ring gear is equal to the output power of the sun gear, that is, the sum of the power of the main drive motor and the speed-regulating motor is equal to the power of the driven equipment.

[0009] After the starting is completed and the normal speed regulation running condition is entered, the main drive motor runs at the power frequency, and the clutch is disengaged. The four-quadrant frequency converter is used to control the speed of the speed-regulating motor. In order to smoothly control the forward and reverse switching condition of the speed-regulating motor, a speed sensor is generally provided. In the starting condition with the synchronous automatic clutch engaged, the planetary speed regulation mechanism becomes a constant speed ratio gear box. The two-quadrant frequency converter and the four-quadrant frequency converter can use the speed sensor for control to achieve better control effect.

[0010] A variety of control modes can be adopted between the two-quadrant frequency converter and the four-quadrant frequency converter. According to the load torque characteristics, the two-quadrant frequency converter and the four-quadrant frequency converter can adopt master-slave control, in which the frequency converter master controls the speed, and the frequency converter master and slave distribute power (torque) in a certain proportion. One of the two-quadrant frequency converter and the four-quadrant frequency converter serves as the frequency converter master, and the other serves as the frequency converter slave. The two-quadrant frequency converter and the four-quadrant frequency converter can also be independently controlled, in which the two-quadrant frequency converter controls the speed, and the four-quadrant frequency converter controls the torque, or vice versa. When there are two four-quadrant frequency converters, the two four-quadrant frequency converters can be controlled in master-slave mode, and can also be controlled in common master-slave mode with the two-quadrant frequency converter.

[0011] The speed regulating motor of the device adopts the railway locomotive motor technology, and the torque characteristic is the horse characteristic. The torque monotonously increases with the decrease of the rotating speed in the whole rotating speed range, and the motor maintains the constant power characteristic in a certain rotating speed range. When the device adopts two speed regulating motors, the two four-quadrant frequency converters adopt master-slave control. When any one of them fails, the other one can still work normally. Due to the horse characteristic of the servo motor, except for the part of the working condition interval close to the upper limit of the rotating speed, one four-quadrant frequency converter can drive one speed regulating motor to maintain normal speed regulating working condition operation. After the failure of the four-quadrant frequency converter, it can be put into operation online again. When both of the four-quadrant frequency converters fail, as long as any one of the speed regulating motors is successfully cut at the power frequency in the positive direction, the device can maintain high rotating speed constant speed operation.

[0012] The speed regulating end idler, the speed regulating end gear, the clutch, the clutch output end gear, the clutch output end two-stage idler, the speed regulating motor, the four-quadrant frequency converter and the speed regulating motor switch in the above scheme can be two or more sets.

[0013] The beneficial effects of the present application are:

[0014] The present application can be used for driving loads with large starting torque. The starting torque can be greater than the rated torque, and the selection of the driving equipment does not have to be increased due to the difficulty in starting the driven equipment.

[0015] The selection of the two-quadrant frequency converter (frequency soft start device) of the main drive motor does not have to select the full capacity. According to the actual load condition, partial capacity can be selected, and it is only used for starting condition and is withdrawn after starting, which does not affect the reliability of normal operation.

[0016] Under the condition of normal selection of the speed regulating motor in the nameplate power, the redundancy of the double motor scheme is high. Single motor operation can meet most of the rotating speed load conditions. It is equivalent to that two speed regulating motors are mutually reserved in normal operation. In the case of failure of one four-quadrant frequency converter, the device operation is basically not affected.

[0017] The present application can realize that the speed regulating motor is cut at the power frequency in the case of all failures of the four-quadrant frequency converter, and the device maintains constant speed operation without stopping operation, so that the four-quadrant frequency converter has the condition of non-stop maintenance of the device, and can be put into operation online after troubleshooting. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 It is a schematic diagram of the shaft structure of the electromechanical integrated planetary speed regulating device.

[0019] In the figure: 1 - main drive motor, 2 - main drive end coupling, 3 - main drive end gear, 4 - inner gear ring, 5 - planet carrier, 6 - sun gear, 7 - output end coupling, 8 - compressor, 9 - speed regulating end idler, 10 - speed regulating end gear, 11 - synchronous automatic clutch, 12 - clutch output end gear, 13 - clutch output end two-stage idler, 14 - speed regulating end coupling, 15 - speed regulating motor.

[0020] Figure 2 Electrical system schematic diagram of the electromechanical integrated planetary speed regulating device.

[0021] In the figure: 1 - main drive motor, 15 - speed regulating motor, 16 - four-quadrant frequency converter, 17 - two-quadrant frequency converter, 18 - bypass switch, 19 - on-site power supply system, 20 - speed regulating motor switch, 21 - main drive motor switch.

[0022] Figure 3 Control method for constant / super-torque starting and running of the electromechanical integrated planetary speed regulating device.

[0023] Figure 4 Control method for constant / super-torque starting and running of the electromechanical integrated planetary speed regulating device.

[0024] Figure 5 Control method for constant / super-torque starting and running of the electromechanical integrated planetary speed regulating device.

[0025] Figure 6 Control method for constant / super-torque starting and running of the electromechanical integrated planetary speed regulating device. Embodiment

[0026] Embodiment 1: A control method for constant / super-torque starting and running of the electromechanical integrated planetary speed regulating device, taking a certain ethylene compressor (hereinafter referred to as: compressor) in a petrochemical industry as an example. The compressor requires a speed regulating range of 70% to 105%, and is equipped with a device rated power of 30000kW. The design speed regulating range is 63% to 105%, and the output speed of the device at the planet carrier static point working condition is 84% of the rated speed. The device includes a main drive motor 1 (24000kW), a main drive end coupling 2, a main drive end gear 3, an inner gear ring 4, a planet carrier 5, a sun gear 6, an output end coupling 7, a compressor 8, a speed regulating end idler 9, a speed regulating end gear 10, a synchronous automatic clutch 11, a clutch output end gear 12, a clutch output end two-stage idler 13, a speed regulating end coupling 14, a speed regulating motor 15 (2x3000kW), and the connection mode is as shown in the figure. Figure 1The shown (two branches of speed regulating power, two sets of identical power branches, only one set is shown in the drawing, that is, it also includes another set of speed regulating end idler 9, speed regulating end gear 10, synchronous automatic clutch 11, clutch output end gear 12, clutch output end two-stage idler 13, speed regulating end shaft 14, speed regulating motor 15), wherein the inner ring gear 4, the planet carrier 5, and the sun gear 6 constitute a differential planetary mechanism, the speed regulating end idler 9 and the speed regulating end gear 10 constitute a speed regulating mechanism of the differential planetary mechanism, the speed regulating end idler 9, the clutch 11, the clutch output end gear 12, the clutch output end two-stage idler 13, and the main drive end gear 3 constitute a main drive motor speed regulating / constant speed clutch mechanism, and the connection mode is as follows Figure 1 The shown also includes a four-quadrant frequency converter 16, a two-quadrant frequency converter 17, a bypass switch 18, a factory power supply system 19, a speed regulating motor switch 20, and a main drive motor switch 21, and the connection mode is as follows Figure 2 The shown.

[0027] The device starts to rise in speed: the main drive motor switch 21 is closed, the two-quadrant frequency converter 17 starts to rise from 0 Hz, drives the main drive motor 1 to rise in speed, the main drive motor 1 drives the main drive end gear 3, the clutch output end two-stage idler 13, the clutch output end gear 12, and the inner ring gear 4 to rise in speed synchronously through the main drive end shaft 2, the inner ring gear 4 drives the planet carrier 5 (in reverse) and the sun gear 6 to rise in speed, the inner ring gear 4 is the power input end of the differential planetary mechanism, the planet carrier 5 and the sun gear 6 are the power output end of the differential planetary mechanism, and the planet carrier 5 drives the speed regulating end idler 9 to rise in speed; at the same time, the speed regulating motor switch 20 is closed, the four-quadrant frequency converter 16 starts to rise in reverse from 0 Hz, drives the speed regulating motor 15 to rise in speed (in reverse), and drives the speed regulating end gear 10 to rise in speed through the speed regulating end shaft 14, thereby driving the speed regulating end idler 9 to rise in speed, at this time, the directions of the actions of the main drive motor 1 and the speed regulating motor 15 on the speed regulating end idler 9 are consistent; the sun gear 6 drives the compressor 8 to rise in speed through the output end shaft 7, due to the resistance torque of the compressor, the speed regulating end idler 9 will continue to rise in speed, when the speed reaches and has a tendency to exceed the clutch output end gear 12, the synchronous automatic clutch 11 is engaged, at this time, the entire differential planetary speed regulating mechanism forms a whole and becomes a constant speed ratio gear box; the power is output from the main drive end shaft 2 to the output end shaft 7 through the differential planetary mechanism 4, 5, and 6, the main drive end gear 3, the inner ring gear 4, the planet carrier 5, the speed regulating end idler 9, the synchronous automatic clutch 11, the clutch output end gear 12, and the clutch output end two-stage idler 13 form a mechanical closed loop and a mechanical circulating power, and the power of the speed regulating motor 15 also acts on the main drive end gear 3 through the speed regulating end shaft 14, the speed regulating end gear 10, the speed regulating end idler 9, the synchronous automatic clutch 11, the clutch output end gear 12, and the clutch output end two-stage idler 13, and the power flow is as follows Figure 3The speed motor 15 reaches the maximum reverse speed (about -100 Hz), the main drive motor 1 reaches the rated speed, and the same phase is checked by the frequency converter. At the same phase point, the bypass switch 18 is turned on, the main drive motor switch 21 is turned off, the main drive motor 1 runs at the power frequency, and the starting process of the device is completed. Then, the frequency of the four-quadrant frequency converter 16 is gradually reduced, the speed of the speed motor 15 is reduced, and the speed of the sun gear 6 is increased. When the speed of the sun gear 6 reaches 70% of the rated speed, the starting process of the compressor is completed, and the device enters the normal speed regulating operation interval. When the speed of the speed motor 15 continuously decreases to zero and increases to the maximum speed (about +100 Hz) in the positive direction, the sun gear 6 reaches the maximum speed (105% of the rated speed).

[0028] The above-mentioned compressor has a design speed of 6000 rpm (100%) and a working speed range of 70% to 105%. The device has a rated power of 30000 kW, a design speed regulating range of 63% to 105%, an output speed of the device at the planetary carrier static point working condition of 84% of the rated speed, a main drive motor power of 24000 kW, a pole number of 4 poles, a power frequency operation, a speed motor power of 3000 kW, a pole number of 6 poles, a torque characteristic of the horse characteristic (a technical characteristic of a railway locomotive motor), a 4000 kW four-quadrant frequency converter (considering the reliability of long-period continuous operation), a working frequency of ±100 Hz, and two sets of each configuration. If the sun gear maintains a constant rated torque output during the 0-63% rated speed starting process, the speed motor always maintains a constant torque (maximum speed corresponding torque) output, when the sun gear reaches 63% of the rated speed, the speed motor reaches the reverse maximum speed (about -100 Hz), the power reaches 3000 kW (electric), the main drive motor also maintains a constant torque (50% rated torque) output, when the speed reaches the rated speed, the power reaches 50% of the rated power, i.e. 12000 kW, and the output power of the device reaches 18000 kW. Since a high-power asynchronous motor basically approaches the rated power factor at about 40% of the load rate, a two-quadrant frequency converter with about 50% of the rated power (12000-12500 kW) can meet the starting needs. Considering the static friction torque of the compressor at zero speed, the output torque of the main drive motor and / or the speed motor during the starting moment of the compressor is greater than the corresponding constant torque in the above-mentioned speed increasing process. Due to the horse characteristic of the speed motor torque, the lower the speed, the greater the torque, so that the device also has a certain degree of torque horse characteristic (the clutch is in the engaged state, and the device is a constant speed ratio gear box at this time). The torque of the main motor is only 50% of the rated torque, and there is sufficient torque margin for overcoming the static friction torque of zero starting speed, as well as greater starting moment of inertia and load torque.

[0029] In the above embodiment, during the starting process, the two speed-adjusting motors, the main drive motor and the compressor are designed according to the constant torque characteristics (the torque upper limit in the running speed range of the device), and the control mode is that the control relationship of the three frequency converters adopts master-slave control. Since the two four-quadrant frequency converters adopt master-slave control in the normal speed-adjusting operation condition, in the starting condition, on the basis of the master-slave control of the two four-quadrant frequency converters, the two-quadrant frequency converter is also taken as a slave machine, the speed is controlled by the master machine of the four-quadrant frequency converter, and the torque is controlled by the slave machine of the four-quadrant frequency converter and the two-quadrant frequency converter. The torque is distributed in proportion, and as a result, the three frequency converters all show constant torque characteristics. Alternatively, the main drive motor and the speed-adjusting motor are independently controlled, the main drive motor adopts constant torque (50% rated torque) control, and the two four-quadrant frequency converters adopt master-slave control, and the master machine controls the speed and the slave machine controls the torque (which is evenly distributed with the master machine), which can also achieve the same control effect.

[0030] If the torque of the compressor in the starting condition is greater than the rated torque, the device can achieve low-speed super-torque to cope with it. When the capacity of the two-quadrant frequency converter configured for the main drive motor is increased, the device can achieve super-rated torque in the starting stage. When the capacity of the two-quadrant frequency converter configured reaches the full capacity, 167% constant rated torque can be achieved in the 0-63% starting process (at the output speed of 63% of the device, the main drive motor and the speed-adjusting motor both maintain rated power output, that is, the device can achieve full power output, 1 / (0.63 / 1.05)≈1.67, which is based on the corresponding torque of the speed-adjusting motor at the highest speed. If the horse characteristics of the speed-adjusting motor are considered, when the output speed of the device is less than 63%, the output torque will be greater than 167% rated torque, and the lower the speed, the greater the torque), which is enough to cope with various harsh conditions in the starting process of the compressor. According to the actual engineering needs, the above parameters can be optimized. The actual starting and running conditions of the compressor are not constant torque characteristics. The device designed according to the constant / super-torque disadvantageous condition will have greater torque margin and working condition adaptability.

[0031] For the case that the starting torque is relatively small and the two speed-adjusting motors realize mechanical soft start through the clutch, the main drive motor can be started by the solid-state soft start device using slope voltage soft grid connection. If the mechanical soft start torque is insufficient to some extent, the torque can be supplemented appropriately to complete the starting, and the solid-state soft start device can still be used to provide torque for the shaft system without using the soft start device based on the frequency conversion principle. For the case that the starting torque is large, according to the starting torque, a two-quadrant frequency converter with appropriate capacity needs to be configured.

[0032] When the device output speed reaches 63%, the main drive motor 1 reaches the rated speed, the bypass switch 18 is turned on at the same point, the main drive motor switch 21 is turned off, the main drive motor 1 is cut off, and the device is in a constant rated torque output state. At this time, the power of the main drive motor 1 is 12000kW, the total power of the two speed regulating motors 15 is 6000kW, and the frequency of the four-quadrant frequency converter 16 is reduced. At this time, the speed regulating motor 15 and the speed regulating end gear 10 and the speed regulating end idler 9 are lowered, and the clutch 11 is disconnected. At the moment, the two speed regulating motors 15 change from the electric state (6000kW) to the feeding state (-6000kW), and the power of the main drive motor 1 rises from 12000kW to 24000kW. The output power of the device remains unchanged (18000kW), and as the device output speed gradually rises to 70%, the output power reaches 20000kW. At this time, the feeding power of the two speed regulating motors 15 is -4000kW, and the power of the main drive motor 1 is still 24000kW. The above is the constant rated torque output state of the device. In the compressor 70% to 105% normal speed regulating operation condition, the speed regulating motor operates according to the constant torque corresponding to the highest speed, and the main drive motor operates according to the constant rated torque (which has been cut off, and the constant rated torque is the constant rated power). The device can still maintain constant rated torque operation. Generally, the pump and the fan have far less than rated torque at partial speed, and only some compressors may exceed rated torque at startup conditions. The present application can meet the requirements. In the device 63% to 105% speed condition, due to the disconnection of the clutch, the power and torque of the speed regulating motor and the main drive motor are related to the speed. Due to the limitation of the rated power of the main drive motor, even if the speed regulating motor has the characteristics of a horse, the device can only maintain the rated torque capacity, and cannot exceed the rated torque. The torque characteristics of the speed regulating motor are approximately linearly increased from 100Hz to nearly 0Hz as the speed decreases, and the constant power characteristics are from 50Hz to 100Hz.

[0033] Because of the torque characteristics of the speed-regulating motor and in the constant power range, the torque of the speed-regulating motor at 50 Hz is twice that at 100 Hz, and the lower the speed, the greater the torque, thus, in operation, if one speed-regulating motor trips, one speed-regulating motor remains normal operation, and still can maintain the constant rated torque output of the device at 73.5% to 94.5% speed, because the shaft power of the compressor is approximately between the square and the cubic of the speed, the shaft power will be significantly reduced at 63% to 73.5% speed, one speed-regulating motor operation, still can meet all operating conditions. The normal operating range characteristics of pumps, fans, compressors and the like are not constant torque, the device can meet the operating conditions between 94.5% to 105% in the case of one speed-regulating motor operation, thus the redundancy is very high, the reliability is very high, even if both sets of four-quadrant frequency converters fail, as long as one speed-regulating motor is successful, the device can be operated at 94.5% speed (just in the compressor operating range, the compressor also has a system to maintain the stability of the process condition), and has the ability to operate at constant rated torque, the speed of the frequency cutting constant speed can be optimized according to the specific situation. When the four-quadrant frequency converter fails, the speed-regulating motor cuts the frequency, the reactor and bypass switch are set, the reactor is limited in time when cutting the frequency to prevent excessive impact, and then the bypass switch is closed. When the four-quadrant frequency converter fails, the frequency converter can be re-operated.

[0034] The device constant (rated) torque operating condition power-speed curve is shown in Figure 6 During the start and normal speed regulation operation of the device, the output power of the device is the area of the OAB line, the power of the main drive motor is the area of the OACDE line, and the power of the speed-regulating motor is the area of the OEF+FDG+GCB line, wherein FDG is the power supply condition, when the output speed of the device is 63%, the main drive motor reaches the rated speed, and the speed-regulating motor reaches the reverse maximum speed, when the output speed of the device is 105%, the speed-regulating motor reaches the forward maximum speed.

[0035] The device constant 167% rated torque start condition power-speed curve is shown in Figure 6 During the start of the device (0-63%), the output power of the device is the area of the OHF line, the power of the main drive motor is the area of the OHE line, and the power of the speed-regulating motor is the area of the OEF line.

[0036] The maximum operating condition power-speed curve of the device with a single speed-regulating motor is shown in Figure 6The output power of the device is the area of the FMNKLB line, the power of the main drive motor is the area of the PMNKLSRQ line, and the power of the speed regulating motor is the area of the FPQG+GRSB line. FPQG is the power of the power supply. It can be seen from the figure that, except for the area of the JMN+KLA line (MN and KL are parabolas), the single motor condition basically covers most of the double motor operating range (the area of the FJAB line). Therefore, the speed regulating motor has a large redundancy.

[0037] If the device is not provided with the synchronous automatic clutch 11, the main drive motor configured with a full-capacity two-quadrant frequency converter (24000 kW) can also achieve constant rated torque starting, but cannot achieve low-speed super-torque.

Claims

1. A control method for constant / super-torque starting and running of a mechatronic planetary speed regulating device, wherein the mechatronic planetary speed regulating device comprises a main drive motor (1), a main drive end gear (3), a differential planetary mechanism, a speed regulating end idler (9), a speed regulating end gear (10), a synchronous automatic clutch (11), a clutch output end gear (12), a clutch output end idler, a speed regulating motor (15), a four-quadrant frequency converter (16), a two-quadrant frequency converter (17), a bypass switch (18), a plant power supply system (19), a speed regulating motor switch (20), and a main drive motor switch (21), the inner ring (4) of the differential planetary mechanism is connected to the main drive end gear (3), the main drive end gear (3) is connected to the clutch output end gear (12) through the clutch output end idler, the clutch output end gear (12) is connected to the output shaft of the synchronous automatic clutch (11), the main drive motor (1) is connected to the main drive end gear (3), the planet carrier (5) of the differential planetary mechanism is connected to the speed regulating end idler (9), the speed regulating end idler (9) and the speed regulating end gear (10) are engaged, the speed regulating end gear (10) is connected to the speed regulating motor (15), the speed regulating end idler (9) is connected to the input shaft of the synchronous automatic clutch (11), one end of the four-quadrant frequency converter (16) is connected to the plant power supply system (19), the other end is connected to the speed regulating motor (15) through the speed regulating motor switch (20), one end of the two-quadrant frequency converter (17) is connected to the plant power supply system (19), the other end is connected to the main drive motor (1) through the main drive motor switch (21), and the main drive motor (1) is also directly connected to the plant power supply system (19) through the bypass switch (18); the sun gear (6) of the differential planetary mechanism is connected to a driven device. characterized in that The control method for constant / super-torque starting and running is as follows: during starting, the main drive motor (1) and the speed regulating motor (15) are controlled by the two-quadrant frequency converter (17) and the four-quadrant frequency converter (16) to work in the motoring condition and jointly bear the load, the differential planetary mechanism becomes a constant-ratio gear box after the synchronous automatic clutch (11) is engaged, the stator synchronous speed of the speed regulating motor (15) is controlled to be higher than the rotor speed to form a slip ratio, or the motor power angle of the speed regulating motor (15) is controlled to make the speed regulating motor (15) work in the motoring condition, the synchronous automatic clutch (11) is always kept in the over-torque state, the synchronous automatic clutch (11) is stably kept in the engaged state, the power of the speed regulating motor (15) and the power of the main drive motor (1) are combined at the main drive end gear (3) to jointly drive the driven device, the input power of the inner ring (4) is equal to the output power of the sun gear (6), i.e., the sum of the power of the main drive motor (1) and the power of the speed regulating motor (15) is equal to the power of the driven device; after starting and entering the normal speed regulating running condition, the main drive motor (1) is cut to run at the power frequency, the synchronous automatic clutch (11) is disengaged, and the four-quadrant frequency converter (16) is used to control the speed of the speed regulating motor (15).

2. The control method of the constant / super-torque starting and running of the electromechanical integrated planetary speed regulation device according to claim 1, characterized in that: The capacity of the two-quadrant frequency converter (17) is selected to meet the condition that (actual power of the speed-regulating motor + actual power of the main drive motor) / actual output speed of the device > rated torque of the device during the starting process, i.e. when the speed-regulating motor (15) and the main drive motor (1) jointly drive the device to accelerate to the rated speed of the main drive motor (1), the actual power of the main drive motor > (rated power of the device x relative output speed of the device) - rated power of the speed-regulating motor, so that the device can realize the starting operation with the output torque exceeding the rated torque.

3. The control method of the constant and super-torque starting and running of the electromechanical integrated planetary speed regulation device according to claim 1, characterized in that: The two-quadrant frequency converter (17) and the four-quadrant frequency converter (16) can adopt various control modes, according to the torque characteristics of the load, the two-quadrant frequency converter (17) and the four-quadrant frequency converter (16) can adopt master-slave control, the frequency converter master controls the speed, and the master-slave frequency converters distribute power in a certain proportion, or can be independently controlled, the two-quadrant frequency converter controls the speed, the four-quadrant frequency converter controls the torque, or the four-quadrant frequency converter controls the speed, and the two-quadrant frequency converter controls the torque; when the four-quadrant frequency converter (16) is two, the two four-quadrant frequency converters are controlled in master-slave mode, and can be controlled in master-slave mode with the two-quadrant frequency converter.

4. The control method of the constant and super-torque starting and running of the electromechanical integrated planetary speed regulation device according to claim 3, characterized in that: In order to stably control the forward and reverse switching conditions of the speed-regulating motor (15), a speed sensor is arranged, under the condition that the synchronous automatic clutch (11) is engaged during the starting condition, the planetary speed-regulating mechanism becomes a constant-ratio gear box, and the two-quadrant frequency converter and the four-quadrant frequency converter are controlled by using the speed sensor, so as to achieve better control effect.

5. The control method of the constant and super-torque starting and running of the electromechanical integrated planetary speed regulation device according to claim 3, characterized in that: The speed-regulating motor (15) adopts the technology of a railway locomotive motor, the torque characteristic is the horse characteristic, the torque monotonously increases with the decrease of the speed in the whole speed range, and the motor maintains the constant power characteristic in a certain speed range; when the device adopts two speed-regulating motors (15), the two four-quadrant frequency converters (16) adopt master-slave control, when any one of the frequency converters fails, the other one can still work normally, due to the horse characteristic of the servo motor, except for the part of the working condition interval close to the upper limit of the speed, one four-quadrant frequency converter driving one speed-regulating motor can maintain the normal speed-regulating working condition operation, after the failure of the four-quadrant frequency converter is eliminated, it can be put into operation online again, when both of the two four-quadrant frequency converters fail, as long as the forward cutting of the power frequency of any one of the speed-regulating motors is successful, the device can maintain the constant speed operation at a high speed.

6. The control method of constant / super-torque starting and running of the mechatronic planetary speed regulation device according to claim 1 or 2 or 3 or 4 or 5, characterized in that: The speed-regulating end idler (9), the speed-regulating end gear (10), the synchronous automatic clutch (11), the clutch output end gear (12), the clutch output end idler, the speed-regulating motor (15), the four-quadrant frequency converter (16) and the speed-regulating motor switch (20) can be two sets.

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