Motor control system and control method

Abstract

The present application relates to a motor control system and a control method, the system comprising a hydraulic system, a rotary actuator and a control module, the hydraulic system being connected to the rotary actuator, and the control module being connected to the hydraulic system and the rotary actuator; the control module being used to control the hydraulic system to utilize the hydraulic oil stored in the accumulator to drive the rotary actuator to drive the motor to rotate, and to control the motor to start after the motor rotor reaches a preset speed, thereby reducing the starting current, which can effectively solve the problem of excessive starting current of high-power motors, increase the service life of the motor, and reduce the impact on the power grid to ensure stable power supply.

Description

Technical Field

[0001] The present application relates to the field of motor technology, and in particular to a motor control system and a control method. Background Art

[0002] As a common rotary actuator, the motor is widely used in industry. Its main function is to generate rotational torque to drive the load to rotate. Since the direct starting current of a high-power motor can reach 5 to 8 times the rated current of the motor in normal operation, it will reduce the service life of the motor. How to reduce the starting current of the motor and increase its service life is an urgent problem to be solved. Summary of the invention

[0003] Based on this, it is necessary to provide a motor control system and control method to address the problem of excessive motor starting current reducing the motor's service life, which can effectively reduce the motor's starting current and increase the motor's service life.

[0004] A motor control system includes a hydraulic system, a rotary actuator and a control module, wherein the hydraulic system is connected to the rotary actuator, and the control module is connected to the hydraulic system and the rotary actuator; the control module is used to control the hydraulic system to use the hydraulic oil stored in the accumulator to drive the rotary actuator to drive the motor to rotate, and control the motor to start after the motor rotor reaches a preset speed.

[0005] A motor control method is implemented based on the above motor control system, and the method includes:

[0006] The control module controls the hydraulic system to drive the rotary actuator to drive the motor to rotate using the hydraulic oil stored in the accumulator, and controls the motor to start after the motor rotor reaches a preset speed.

[0007] The above-mentioned motor control system and control method, when starting the motor, controls the hydraulic system through the control module to use the hydraulic oil stored in the accumulator to drive the rotary actuator to drive the motor to rotate, and controls the motor to start after the motor rotor reaches a preset speed, thereby reducing the starting current. It can effectively solve the problem of excessive starting current of high-power motors, increase the service life of the motor, and reduce the impact on the power grid to ensure stable power supply. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 Schematic diagram of the structure of a motor control system in one embodiment.

[0009] Explanation of the accompanying drawings: 1-oil tank, 2-overflow valve, 3-hydraulic pump-motor, 41-first clutch, 42-second clutch, 5-dual-axis three-phase motor, 6-torque sensor, 7-brake disc, 8-speed sensor, 9-hydraulic brake, 101-second connecting rod, 102-first connecting rod, 11-single-acting spring return hydraulic cylinder, 12-single-acting spring return hydraulic cylinder, 13-two-position two-way solenoid reversing valve, 14-pressure sensor, 15-cartridge valve, 16-stop valve, 17-accumulator, 18-two-position three-way solenoid reversing valve, 191-two-position three-way solenoid reversing valve, 192-two-position three-way solenoid reversing valve, 193-two-position three-way solenoid reversing valve, 20-load. DETAILED DESCRIPTION

[0010] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0011] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0012] It will be appreciated that spatial relationship terms such as "under," "beneath," "below," "under," "above," "above," etc., may be used herein to describe the relationship of an element or feature shown in the figures to other elements or features. It will be appreciated that, in addition to the orientations shown in the figures, spatial relationship terms also include different orientations of the device in use and operation. For example, if the device in the accompanying drawings is flipped, an element or feature described as "under other elements" or "under it" or "under it" will be oriented as being "above" the other elements or features. Thus, the exemplary terms "under" and "under" may include both upper and lower orientations. In addition, the device may also include additional orientations (e.g., rotated 90 degrees or other orientations), and the spatial descriptors used herein are interpreted accordingly.

[0013] It should be noted that when an element is considered to be "connected" to another element, it can be directly connected to the other element, or connected to the other element through an intermediate element. The "connection" in the following embodiments should be understood as "electrical connection", "communication connection", etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0014] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the terms used in this specification include any and all combinations of the relevant listed items.

[0015] In one embodiment, Figure 1 As shown, a motor control system is provided, including a hydraulic system, a rotary actuator 200 and a control module, wherein the hydraulic system is connected to the rotary actuator 200, and the control module is connected to the hydraulic system and the rotary actuator 200; the control module is used to control the hydraulic system to drive the rotary actuator 200 to drive the motor to rotate using the hydraulic oil stored in the accumulator, and control the motor to start after the motor rotor reaches a preset speed. Among them, the specific type of the control module is not unique, and can be a CPU (Central Processing Unit), an MCU (Micro Control Unit, in Chinese, a micro control unit), an FPGA (Field Programmable Gate Array, field programmable logic gate array), etc. When the motor needs to be started, the control module controls the hydraulic system to drive the rotary actuator 200 to drive the motor to rotate using the hydraulic oil stored in the accumulator, and controls the motor to start after the motor rotor reaches a preset speed, thereby reducing the starting current and effectively solving the problem of excessive starting current of high-power motors.

[0016] Specifically, the hydraulic system may include an accumulator energy storage and release control circuit 110, a first clutch control circuit 120, a second clutch control circuit 130 and a brake control circuit 140; the accumulator energy storage and release control circuit 110 is connected to the rotary actuator 200, the first clutch control circuit 120, the second clutch control circuit 130 and the brake control circuit 140, the rotary actuator 200 is connected to the first clutch control circuit 120, the second clutch control circuit 130 and the brake control circuit 140, and the control module is connected to the accumulator energy storage and release control circuit 110, the first clutch control circuit 120, the second clutch control circuit 130 and the brake control circuit 140. Among them, the accumulator energy storage and release control circuit 110 is used to control the storage and release of hydraulic oil, the first clutch control circuit 120 is used to control whether the motor rotates, the second clutch control circuit 130 is used to control whether the motor drives the load, and the brake control circuit 140 is used to brake the rotary actuator 200.

[0017] Furthermore, in one embodiment, the control module is further used to control the hydraulic system to use the hydraulic oil stored in the accumulator to drive the motor to separate from the load, and then connect the motor to the load after starting the motor without load. When starting the motor, first separate the motor from the load, start the motor without load, and then connect the motor and the load, which can further achieve the effect of reducing the starting current.

[0018] In one embodiment, the control module is also used to control the hydraulic system to use the hydraulic oil stored in the accumulator to drive the motor to separate from the load, then cut off the power supply of the motor, and clamp the brake disc. When braking, first separate the normally operating motor from the load, then cut off the power supply of the motor, and at the same time release the hydraulic oil to drive the brake in the brake control circuit 140 to clamp the brake disc in the rotary actuator 200, so that the excess torque generated by the motor rotor inertia during braking can be eliminated, so that the braking process only needs to overcome the torque generated by the load inertia, which is conducive to shortening the braking time, improving the braking efficiency, and eliminating the damage to the motor structure caused by the impact of the sudden stop of the load during the braking process.

[0019] In one embodiment, the control module is also used to control the hydraulic system to use the hydraulic oil stored in the accumulator to compensate for the motor torque in short-term overload operation. By releasing the hydraulic oil stored in the accumulator in the hydraulic system, the rotary actuator 200 is driven to drive the motor to rotate, and the motor torque in short-term overload operation is compensated to avoid burning the motor due to overheating caused by motor shutdown.

[0020] It is understood that the specific structure of the accumulator storage and release control circuit 110 is not unique. In one embodiment, Figure 1 As shown, the accumulator energy storage and release control circuit 110 includes a fuel tank 1, a first reversing valve, a cartridge valve 15, a pressure sensor 14, an accumulator 17 and a second reversing valve; the fuel tank 1 is connected to the first reversing valve, the second reversing valve, the first clutch control circuit 120, the second clutch control circuit 130, the brake control circuit 140 and the rotary actuator 200; the cartridge valve 15 is connected to the first reversing valve, the second reversing valve, the accumulator 17, the first clutch control circuit 120, the second clutch control circuit 130 and the brake control circuit 140; the pressure sensor 14 is connected to the accumulator 17 and the control module; the control module is connected to the first reversing valve and the second reversing valve.

[0021] Among them, the specific types of the first reversing valve and the second reversing valve are not unique. In this embodiment, the first reversing valve is a two-position two-way electromagnetic reversing valve 13, and the second reversing valve is a two-position three-way electromagnetic reversing valve 18. The accumulator 17 is used to store or release hydraulic oil. The two-position two-way electromagnetic reversing valve 13 is used to control the on-off of the accumulator 17 during the storage and release of hydraulic oil; the cartridge valve 15 and the two-position three-way electromagnetic reversing valve 18 are used in conjunction to control the opening and closing of the accumulator 17, wherein the cartridge valve 15 can also reduce the leakage of hydraulic oil in the accumulator 17; the pressure sensor 14 is used to detect the pressure at the outlet of the accumulator 17 and provide real-time feedback to the control module.

[0022] Furthermore, in one embodiment, the accumulator energy storage and release control circuit 110 may also include a relief valve 2 and a stop valve 16, and the oil tank 1 is connected to the two-position two-way electromagnetic reversing valve 13 and the rotary actuator 200 through the relief valve 2. The accumulator 17 is connected to the cartridge valve 15, the two-position three-way electromagnetic reversing valve 18 and the pressure sensor 14 through the stop valve 16. The relief valve 2 is used to limit the maximum working pressure of the accumulator 17 in the system, and plays a safety protection role. The stop valve 16 is used to cut off the connection between the accumulator 17 and the hydraulic system circuit. The stop valve 16 is set to facilitate the installation, removal, replacement and maintenance of the accumulator 17. Once the accumulator 17 is installed in the hydraulic system, under normal circumstances, the stop valve 16 is in a fully open state.

[0023] In one embodiment, the first clutch control circuit 120 includes a third reversing valve and a first reset hydraulic cylinder, the third reversing valve is connected to the control module, the oil tank 1, the cartridge valve 15 and the first reset hydraulic cylinder, and the first reset hydraulic cylinder is connected to the rotary actuator 200. The third reversing valve can be specifically a two-position three-way electromagnetic reversing valve 191, and the first reset hydraulic cylinder can be specifically a single-acting spring reset hydraulic cylinder 12. The two-position three-way electromagnetic reversing valve 191 and the cartridge valve 15 are used in conjunction to control the opening and closing of the oil circuit between the accumulator 17 and the single-acting spring reset hydraulic cylinder 12.

[0024] In one embodiment, continue to refer to Figure 1 The second clutch control circuit 130 includes a fourth reversing valve and a second reset hydraulic cylinder, the fourth reversing valve is connected to the control module, the oil tank 1, the cartridge valve 15 and the second reset hydraulic cylinder, and the second reset hydraulic cylinder is connected to the rotary actuator 200. The fourth reversing valve can be specifically a two-position three-way electromagnetic reversing valve 192, and the second reset hydraulic cylinder can be specifically a single-acting spring reset hydraulic cylinder 11. The two-position three-way electromagnetic reversing valve 192 and the cartridge valve 15 are used in conjunction to control the opening and closing of the oil circuit between the accumulator 17 and the single-acting spring reset hydraulic cylinder 11.

[0025] In one embodiment, the brake control circuit 140 includes a fifth reversing valve and a hydraulic brake 9, wherein the fifth reversing valve is connected to the control module, the oil tank 1, the cartridge valve 15 and the hydraulic brake 9, and the hydraulic brake 9 is connected to the rotary actuator 200. The fifth reversing valve can specifically be a two-position three-way electromagnetic reversing valve 193. The two-position three-way electromagnetic reversing valve 193 and the cartridge valve 15 are used in conjunction to control the opening and closing of the oil circuit between the accumulator 17 and the hydraulic brake 9.

[0026] The specific structure of the rotary actuator 200 is also not unique. In one embodiment, Figure 1 As shown, the rotary actuator includes a hydraulic pump-motor 3, a first clutch 41, a first connecting rod 102, a motor, a second clutch 42, a second connecting rod 101, a torque sensor 6, a brake disc 7 and a speed sensor 8; the hydraulic pump-motor 3 is connected to the oil tank 1, the first reversing valve (specifically a two-position two-way electromagnetic reversing valve 13) and the first clutch 41, the first clutch 41 is connected to the first connecting rod 102 and the motor, and the first connecting rod 102 is connected to the first clutch control circuit 120. The motor is connected to the second clutch 42 and the control module, the second clutch 42 is connected to the second connecting rod 101 and the torque sensor 6, and the second connecting rod 101 is connected to the second clutch control circuit 130. The torque sensor 6 is connected to the control module and the brake disc 7, the brake disc 7 is connected to the brake control circuit 140 and the speed sensor 8, and the speed sensor 8 is connected to the control module and the load 20.

[0027] Specifically, the motor can be a dual-axis three-phase motor 5, and the first connecting rod 102 is connected to the single-acting spring return hydraulic cylinder 12 in the first clutch control circuit 120, and the single-acting spring return hydraulic cylinder 12 can apply force to the first connecting rod 102 to separate or engage the first clutch 41. The second connecting rod 101 is connected to the single-acting spring return hydraulic cylinder 11 in the second clutch control circuit 130, and the single-acting spring return hydraulic cylinder 11 can apply force to the second connecting rod 101 to separate or engage the second clutch 42. The brake disc 7 is connected to the hydraulic brake 9 in the brake control circuit 140, and the hydraulic brake 9 can clamp or release the brake disc 7, thereby achieving braking or non-braking of the load 20.

[0028] The hydraulic pump-motor 3 is a hydraulic motor with a special structure. When the hydraulic oil drives the hydraulic pump-motor 3 to rotate forward, the hydraulic pump-motor 3 is used as a conventional hydraulic motor. When the motive force drives the hydraulic pump-motor 3 to rotate reversely, the hydraulic pump-motor 3 can be used as a hydraulic pump. The first clutch 41 is used to realize the separation and engagement of the hydraulic pump-motor 3 and the double-shaft three-phase motor 5; the second clutch 42 is used to realize the separation and engagement of the double-shaft three-phase motor 5 and the load 20; the first clutch 41 and the second clutch 42 are in an engaged state when not subjected to the pressure of the first connecting rod 102 and the second connecting rod 101; the double-shaft three-phase motor 5 can be connected to the hydraulic pump-motor 3 and the load 20 respectively through the first clutch 41 and the second clutch 42, and the double-shaft three-phase motor 5 can realize forward and reverse rotation; the torque sensor 6 is installed between the second clutch 42 and the load 20, and is used to detect the torque of the load 20 and provide real-time feedback to the control module. The brake disc 7 is installed between the second clutch 42 and the load 20, and the brake disc 7 is used in conjunction with the hydraulic brake 9 to realize braking. The speed sensor 8 is installed on the shaft of the load 20, and is used to detect the speed of the load 20 and provide real-time feedback to the control module. The control module can receive the feedback signals of the pressure sensor 14 and the torque sensor 6 in the system in real time, and can control the on and off of the two-position two-way electromagnetic reversing valve 13, the two-position three-way electromagnetic reversing valve 18, and the two-position three-way electromagnetic reversing valves 191, 192, 193. The control module can also control the power on, power off, forward rotation and reverse rotation of the dual-axis three-phase motor 5.

[0029] The following is a further explanation in conjunction with the working process of the motor control system.

[0030] The system is in the following state before normal operation:

[0031] Before the accumulator 17 is installed in the hydraulic system circuit, a certain amount of hydraulic oil must be pre-charged so that the pressure in the accumulator 17 can simultaneously supply the first clutch control circuit 120, the second clutch control circuit 130 and the brake control circuit 140 to perform corresponding actions, and the minimum pressure in the accumulator 17 at this time is assumed to be P1. The stop valve 16 is in a fully open state, the two-position two-way electromagnetic reversing valve 13, the two-position three-way electromagnetic reversing valve 18 and the two-position three-way electromagnetic reversing valves 191, 192, 193 are not energized and are in the left position, and the overflow valve 2 has set the system's maximum working pressure Pmax. The single-acting spring return hydraulic cylinder 12 pushes the first connecting rod 102 under the action of the return spring to apply a pressure to the first clutch 41, so that the first clutch 41 is in a disengaged state; the single-acting spring return hydraulic cylinder 11 pulls back the second connecting rod 101 under the action of the return spring, and does not exert force on the second clutch 42, and the second clutch 42 is in an engaged state; when there is no hydraulic pressure on the hydraulic brake 9, the hydraulic brake 9 is separated from the brake disc 7, and there is no braking effect at this time.

[0032] The process of storing hydraulic energy in the accumulator 17 is as follows:

[0033] The control module first controls the two-position three-way electromagnetic reversing valve 18 to be energized and opened, and the cartridge valve 15 is opened at this time. Then the two-position three-way electromagnetic reversing valves 191 and 192 are simultaneously controlled to be energized and opened. At this time, the hydraulic oil in the accumulator 17 flows to the single-acting spring return hydraulic cylinder 12 through the cartridge valve 15 and the two-position three-way electromagnetic reversing valve 191. Under the action of the hydraulic oil, the piston rod of the single-acting spring return hydraulic cylinder 12 is pushed back to the rodless cavity and the first connecting rod 102 is pulled, so that the first clutch 41 is not stressed, and the first clutch 41 is in the engaged state. At the same time, the hydraulic oil in the accumulator 17 also flows to the single-acting spring return hydraulic cylinder 11 through the cartridge valve 15 and the two-position three-way electromagnetic reversing valve 192. Under the action of the hydraulic oil, the piston rod of the single-acting spring return hydraulic cylinder 11 is pushed to extend to the rod cavity and the second connecting rod 101 is pushed to apply a pressure to the second clutch 42, so that the second clutch 42 is in the disengaged state. At this time, the dual-shaft three-phase motor 5 is separated from one side of the load 20 and is engaged with the hydraulic pump-motor 3 , and the dual-shaft three-phase motor 5 is in a light-load state.

[0034] The control module controls the two-position two-way electromagnetic reversing valve 13 to be powered on and turned on. At the same time, the control module controls the double-axis three-phase motor 5 to rotate in the opposite direction, drives the hydraulic pump-motor 3 to rotate in the opposite direction through the first clutch 41, and charges the accumulator 17 with hydraulic oil. At this time, the hydraulic pump-motor 3 is used as a hydraulic pump. When the pressure sensor 14 detects that the pressure at the outlet of the accumulator 17 reaches the set value, the control module first controls the two-position two-way electromagnetic reversing valve 13 to be powered off and closed, and then controls the two-position three-way electromagnetic reversing valve 18 and the two-position three-way electromagnetic reversing valves 191 and 192 to be powered off and closed. At this time, the cartridge valve 15 is also closed due to the closure of the two-position three-way electromagnetic reversing valve 18. At this point, the process of storing hydraulic energy in the accumulator 17 is completed, and it is ready for the next start of the motor and compensation of the motor torque.

[0035] The process of starting the dual-axis three-phase motor 5 with load is as follows:

[0036] The control module controls the two-position three-way electromagnetic reversing valve 18 to be energized and opened, at which time the cartridge valve 15 is opened, and the control module controls the two-position three-way electromagnetic reversing valve 191 to be energized and opened, and the hydraulic oil in the accumulator 17 flows to the single-acting spring return hydraulic cylinder 12 through the cartridge valve 15 and the two-position three-way electromagnetic reversing valve 191. Under the action of the hydraulic oil, the piston rod of the single-acting spring return hydraulic cylinder 12 is pushed back to the rodless cavity and the first connecting rod 102 is pulled, so that the first clutch 41 is not stressed, and the first clutch 41 is in the engaged state. Because the two-position three-way electromagnetic reversing valves 192 and 193 are in the de-energized closed state, the second clutch 42 is in the engaged state, and the hydraulic brake 9 is also in the unbraking state. Then the control module controls the two-position two-way electromagnetic reversing valve 13 to be powered on, and the high-pressure hydraulic oil in the accumulator 17 drives the hydraulic pump-motor 3 through the cartridge valve 15 and the two-position two-way electromagnetic reversing valve 13 to drive the dual-axis three-phase motor 5 and the load 20 to rotate forward. At this time, the hydraulic pump-motor 3 is used as a hydraulic motor. When the speed sensor 8 detects that the speed of the load 20 reaches a certain value, the control module simultaneously controls the two-position three-way electromagnetic reversing valve 18, the two-position two-way electromagnetic reversing valve 13 and the two-position three-way electromagnetic reversing valve 191 to be powered off and closed. At this time, the accumulator 17 no longer supplies oil to the hydraulic pump-motor 3 and the single-acting spring return hydraulic cylinder 12, and the hydraulic pump-motor 3 stops rotating. The first clutch 41 is in a disengaged state under the push of the single-acting spring return hydraulic cylinder 12, so that the hydraulic pump-motor 3 and the dual-axis three-phase motor 5 are separated. At the same time, the control module controls the dual-axis three-phase motor 5 to be powered on, so that the dual-axis three-phase motor 5 and the load 20 start at a certain speed, thereby reducing the starting current of the dual-axis three-phase motor 5 when starting with the load 20.

[0037] The process of starting the dual-axis three-phase motor 5 without load and then connecting the load 20 is as follows:

[0038] The control module controls the two-position three-way electromagnetic reversing valve 18 to be energized and opened, at which time the cartridge valve 15 is opened, and the control module controls the two-position three-way electromagnetic reversing valve 192 to be energized and opened, and the hydraulic oil in the accumulator 17 flows to the single-acting spring return hydraulic cylinder 11 through the cartridge valve 15 and the two-position three-way electromagnetic reversing valve 192. Under the action of the hydraulic oil, the piston rod of the single-acting spring return hydraulic cylinder 11 is pushed to extend to the rod chamber and push the second connecting rod 101 to apply a pressure to the second clutch 42, so that the second clutch 42 is in a disengaged state. Because the two-position three-way electromagnetic reversing valve 191 is in a de-energized closed state, the first clutch 41 is also in a disengaged state. At this time, that is, when the dual-axis three-phase motor 5 is neither connected to the hydraulic pump-motor 3 nor to the load 20, the control module controls the dual-axis three-phase motor 5 to start rotating in the forward direction. When the speed of the dual-axis three-phase motor 5 is stable, the control module controls the two-position three-way electromagnetic reversing valve 192 and the two-position three-way electromagnetic reversing valve 18 to lose power and close. At this time, the cartridge valve 15 is also closed, and the accumulator 17 no longer supplies oil to the single-acting spring return hydraulic cylinder 11. The second clutch 42 resumes the engagement state under the action of the single-acting spring return hydraulic cylinder 11. At this time, the dual-axis three-phase motor 5 is started without load first, and then the load 20 is connected, so as to reduce the starting current of the dual-axis three-phase motor 5 when working with the load 20.

[0039] The braking process of a dual-axis three-phase motor with a load of 5 and 20 is as follows:

[0040] When the dual-axis three-phase motor 5 with load 20 needs to brake during operation, the control module controls the two-position three-way solenoid reversing valve 18 to be energized and opened. At this time, the cartridge valve 15 is opened, and the control module controls the two-position three-way solenoid reversing valve 192 to be energized and opened. The hydraulic oil in the accumulator 17 flows to the single-acting spring return hydraulic cylinder 11 through the cartridge valve 15 and the two-position three-way solenoid reversing valve 192. Under the action of the hydraulic oil, the piston rod of the single-acting spring return hydraulic cylinder 11 is pushed to extend into the rod cavity and push the second connecting rod 101 to apply a pressure to the second clutch 42, so that the second clutch 42 is in a disengaged state. When the dual-axis three-phase motor 5 is separated from one side of the load 20, the control module controls the dual-axis three-phase motor 5 to be powered off and stopped, and at the same time, the control module controls the two-position three-way electromagnetic reversing valve 193 to be powered on. Since the two-position three-way electromagnetic reversing valve 18 and the cartridge valve 15 are both open, the hydraulic oil in the accumulator 17 drives the hydraulic brake 9 to clamp the brake disc 7 through the cartridge valve 15 and the two-position three-way electromagnetic reversing valve 193, thereby achieving the braking of the load 20 carried by the dual-axis three-phase motor 5. Since the dual-axis three-phase motor 5 and one side of the load 20 have been separated during the braking process, the braking process only needs to overcome the torque generated by the load inertia, which is conducive to shortening the braking time, improving the braking efficiency, and eliminating the damage to the structure of the dual-axis three-phase motor 5 caused by the impact caused by the sudden stop of the load 20 during the braking process.

[0041] The system compensates the motor torque in short-term overload operation as follows:

[0042] When the double-shaft three-phase motor 5 drives the load 20 to operate normally, the double-shaft three-phase motor 5 and the hydraulic pump-motor 3 are separated. When the torque sensor 6 detects that the torque on the rotating shaft on one side of the load 20 suddenly increases, and the speed sensor 8 detects that the speed of the load 20 decreases significantly, the control module determines that the double-shaft three-phase motor 5 is in an overload operation state. At this time, the control module controls the two-position three-way electromagnetic reversing valve 18 to be energized and opened, and the cartridge valve 15 is opened. The control module then controls the two-position three-way electromagnetic reversing valve 191 to be energized and opened, and the hydraulic oil in the accumulator 17 flows to the single-acting spring return hydraulic cylinder 12 through the cartridge valve 15 and the two-position three-way electromagnetic reversing valve 191. Under the action of the hydraulic oil, the piston rod of the single-acting spring return hydraulic cylinder 12 is pushed back to the rodless cavity and the first connecting rod 102 is pulled, so that the first clutch 41 is not stressed. At this time, the first clutch 41 is in an engaged state. Then, the control module controls the two-position two-way solenoid reversing valve 13 to be energized and opened, and the high-pressure hydraulic oil in the accumulator 17 drives the hydraulic pump-motor 3 through the cartridge valve 15 and the two-position two-way solenoid reversing valve 13 to drive the double-axis three-phase motor 5 and the load 20 to rotate forward, so that the double-axis three-phase motor 5 can smoothly overcome the working condition of insufficient motor output torque due to short-term overload operation.

[0043] After the accumulator 17 releases hydraulic energy once, the control module simultaneously controls the two-position three-way solenoid reversing valve 18, the two-position two-way solenoid reversing valve 13 and the two-position three-way solenoid reversing valve 191 to lose power and close. At this time, the accumulator 17 no longer supplies oil to the hydraulic pump-motor 3 and the single-acting spring return hydraulic cylinder 12, the hydraulic pump-motor 3 stops rotating, and the first clutch 41 is in a disengaged state under the push of the single-acting spring return hydraulic cylinder 12, so that the hydraulic pump-motor 3 and the dual-axis three-phase motor 5 are separated.

[0044] If the accumulator 17 still cannot make the dual-axis three-phase motor 5 cross the overload operating condition after releasing the hydraulic energy once, that is, the torque sensor 6 detects that the torque on the shaft on one side of the load 20 is always large, and the speed sensor 8 detects that the speed of the load 20 is always small, then the control module controls the two-position three-way electromagnetic reversing valve 18 to be energized and opened, and the cartridge valve 15 is opened at this time, and the control module controls the two-position three-way electromagnetic reversing valve 192 to be energized and opened, and the hydraulic oil in the accumulator 17 flows to the single-acting spring return hydraulic cylinder 11 through the cartridge valve 15 and the two-position three-way electromagnetic reversing valve 192. Under the action of the hydraulic oil, the piston rod of the single-acting spring return hydraulic cylinder 11 is pushed to extend to the rod cavity and push the second connecting rod 101 to apply a pressure to the second clutch 42, so that the second clutch 42 is in a disengaged state. Then, the control module controls the dual-axis three-phase motor 5 to be powered off and stopped. In this way, the dual-axis three-phase motor 5 and the load 20 are separated, thereby avoiding the risk of the dual-axis three-phase motor 5 stalling due to being unable to drive the load 20 and burning the motor.

[0045] In addition, when the pressure sensor 14 detects that the outlet pressure of the accumulator 17 is equal to P1 (P1 is the minimum pressure in the accumulator 17 that can simultaneously supply the first clutch control circuit 120, the second clutch control circuit 130 and the brake control circuit 140 to perform corresponding actions), the control module executes the above-mentioned process of storing hydraulic energy in the accumulator 17. In this way, it is ensured that each time the accumulator 17 releases hydraulic energy, there is still a certain pressure to achieve the separation and engagement of the first clutch 41 and the second clutch 42, and to achieve braking of the load 20, thereby ensuring the safety and normal operation of the system.

[0046] In one embodiment, a motor control method is also provided, which is implemented based on the above motor control system. The method includes: a control module controls the hydraulic oil stored in the accumulator in the hydraulic system to drive the rotary actuator to drive the motor to rotate, and controls the motor to start after the motor rotor reaches a preset speed. Specifically, the process of starting the motor with load includes the following steps:

[0047] The control module controls the second reversing valve to be powered on, the cartridge valve 15 is opened, and the control module controls the third reversing valve to be powered on. The hydraulic oil in the accumulator 17 flows to the first reset hydraulic cylinder through the cartridge valve 15 and the third reversing valve. Under the action of the hydraulic oil, the piston rod of the first reset hydraulic cylinder is pushed back to the rodless cavity and the first connecting rod 102 is pulled, so that the first clutch 41 is not stressed. At this time, the first clutch 41 is in the engaged state; the fourth reversing valve and the fifth reversing valve are in the power-off closed state, the second clutch 42 is in the engaged state, and the hydraulic brake 9 is also in the non-braking state;

[0048] The control module controls the first reversing valve to be powered on, and the high-pressure hydraulic oil in the accumulator 17 drives the hydraulic pump-motor 3 through the cartridge valve 15 and the first reversing valve to drive the motor and the load 20 to rotate in the forward direction, and the hydraulic pump-motor 3 is used as a hydraulic motor; when the speed sensor 8 detects that the speed of the load 20 reaches the preset value, the control module simultaneously controls the second reversing valve, the first reversing valve and the third reversing valve to be powered off and closed. At this time, the accumulator 17 no longer supplies oil to the hydraulic pump-motor 3 and the first reset hydraulic cylinder, the hydraulic pump-motor 3 stops rotating, and the first clutch 41 is in a disengaged state under the push of the first reset hydraulic cylinder, so that the hydraulic pump-motor 3 and the motor are separated; at the same time, the control module controls the motor to be powered on, so that the motor and the load 20 are started at a speed, thereby reducing the starting current when the motor starts with the load 20.

[0049] In one embodiment, the method further includes: the control module controls the hydraulic oil stored in the accumulator in the hydraulic system to drive the motor in the rotary actuator to separate from the load, and then connect the motor to the load after starting the motor without load. Specifically, the process of starting the motor without load first and then connecting the load includes the following steps:

[0050] The control module controls the second reversing valve to be powered on, at which time the cartridge valve 15 is opened, and the control module controls the fourth reversing valve to be powered on, and the hydraulic oil in the accumulator 17 flows to the second reset hydraulic cylinder through the cartridge valve 15 and the fourth reversing valve. Under the action of the hydraulic oil, the piston rod of the second reset hydraulic cylinder is pushed to extend to the rod chamber and the second connecting rod 101 is pushed to apply pressure to the second clutch 42, so that the second clutch 42 is in a disengaged state; the third reversing valve is in a power-off closed state, and the first clutch 41 is also in a disengaged state; when the motor is neither connected to the hydraulic pump-motor 3 nor to the load 20, the control module controls the motor to rotate forward and start, and when the motor speed is stable, the control module controls the fourth reversing valve and the second reversing valve to be powered off and closed, at which time the cartridge valve 15 is closed, and the accumulator 17 no longer supplies oil to the second reset hydraulic cylinder, and the second clutch 42 resumes the engaged state under the action of the second reset hydraulic cylinder. At this time, the motor is started without load first, and then the load 20 is connected, so as to reduce the starting current of the motor when it works with the load 20.

[0051] In one embodiment, the method further includes: when the system is braking, the control module controls the hydraulic oil stored in the accumulator in the hydraulic system to drive the motor in the rotary actuator to separate from the load, then cuts off the power supply of the motor, and clamps the brake disc in the rotary actuator. Specifically, the motor load braking process includes the following steps:

[0052] When the motor with load 20 needs to brake during operation, the control module controls the second reversing valve to be energized and opened. At this time, the cartridge valve 15 opens, and the control module controls the fourth reversing valve to be energized and opened. The hydraulic oil in the accumulator 17 flows to the second reset hydraulic cylinder through the cartridge valve 15 and the fourth reversing valve. Under the action of the hydraulic oil, the piston rod of the second reset hydraulic cylinder is pushed to extend to the rod chamber and push the second connecting rod 101 to apply pressure to the second clutch 42, so that the second clutch 42 is in a disengaged state.

[0053] When the motor and one side of the load 20 are separated, the control module controls the motor to be powered off and stop, and at the same time, the control module controls the fifth reversing valve to be powered on and opened. Since the second reversing valve and the cartridge valve 15 are both opened, the hydraulic oil in the accumulator 17 drives the hydraulic brake 9 to clamp the brake disc 7 through the cartridge valve 15 and the fifth reversing valve.

[0054] In one embodiment, the method further includes: the control module controls the hydraulic oil stored in the accumulator in the hydraulic system to drive the hydraulic pump-motor in the rotary actuator to rotate, so that the hydraulic pump-motor compensates for the motor torque in short-term overload operation. Specifically, the process of compensating the motor torque in short-term overload operation includes the following steps:

[0055] When the motor drives the load 20 in normal operation, the motor and the hydraulic pump-motor 3 are separated. When the torque sensor 6 detects that the torque on the rotating shaft on one side of the load 20 increases, and the speed sensor 8 detects that the speed of the load 20 decreases, the control module determines that the motor is in an overload operation state. The control module controls the second reversing valve to be powered on, the cartridge valve 15 is opened, and the control module controls the third reversing valve to be powered on. The hydraulic oil in the accumulator 17 flows to the first reset hydraulic cylinder through the cartridge valve 15 and the third reversing valve. Under the action of the hydraulic oil, the piston rod of the first reset hydraulic cylinder is pushed back to the rodless chamber and the first connecting rod 102 is pulled, so that the first clutch 41 is not stressed. At this time, the first clutch 41 is in an engaged state.

[0056] The control module controls the first reversing valve to be powered on, and the high-pressure hydraulic oil in the accumulator 17 drives the hydraulic pump-motor 3 through the cartridge valve 15 and the first reversing valve to drive the motor and the load 20 to rotate in the forward direction, so that the motor can smoothly overcome the working condition where the motor output torque is insufficient due to short-term overload operation.

[0057] After the accumulator 17 releases hydraulic energy once, the control module simultaneously controls the second reversing valve, the first reversing valve and the third reversing valve to lose power and close, the accumulator 17 no longer supplies oil to the hydraulic pump-motor 3 and the first reset hydraulic cylinder, the hydraulic pump-motor 3 stops rotating, and the first clutch 41 is in a disengaged state under the push of the first reset hydraulic cylinder, so that the hydraulic pump-motor 3 and the motor are separated.

[0058] If the accumulator 17 still cannot make the motor cross the overload operating condition after releasing the hydraulic energy once, that is, the torque sensor 6 detects that the torque on the rotating shaft on one side of the load 20 is always large, and the speed sensor 8 detects that the speed of the load 20 is always small, then the control module controls the second reversing valve to be powered on, and the cartridge valve 15 is opened at this time, and the control module controls the fourth reversing valve to be powered on, and the hydraulic oil in the accumulator 17 flows to the second reset hydraulic cylinder through the cartridge valve 15 and the fourth reversing valve. Under the action of the hydraulic oil, the piston rod of the second reset hydraulic cylinder is pushed to extend to the rod cavity and the second connecting rod 101 is pushed to apply pressure to the second clutch 42, so that the second clutch 42 is in a disengaged state; the control module controls the motor to be powered off and stopped. In this way, the motor and the load 20 are separated, avoiding the risk of the motor burning due to the motor stalling due to the inability to carry the load 20.

[0059] It should be noted that the specific embodiments of the above motor control method refer to the embodiments of the above motor control system and will not be repeated here.

[0060] The above-mentioned motor control method, when starting the motor, controls the hydraulic oil stored in the accumulator in the hydraulic system through the control module to drive the rotary actuator to drive the motor to rotate, and controls the motor to start after the motor rotor reaches a preset speed, thereby reducing the starting current. It can effectively solve the problem of excessive starting current of high-power motors, increase the service life of the motor, and reduce the impact on the power grid to ensure stable power supply.

[0061] In order to facilitate a better understanding of the above motor control system and control method, a detailed explanation is given below in conjunction with specific embodiments.

[0062] Since the current of high-power motor direct starting can reach 5 to 8 times the rated current of the motor in normal operation, it will not only damage the electrical equipment and reduce the service life of the motor, but also cause impact on the power grid and affect the stability of power supply. Therefore, people have come up with methods such as star-delta starting, auto-coupling pressure-reducing starting, soft starting and variable frequency starting to effectively reduce the harm caused by excessive current caused by direct motor starting. However, star-delta starting and auto-coupling pressure-reducing starting methods are only suitable for no-load or light-load starting occasions; the soft starting method uses thyristor components, which will not only generate large harmonic interference during operation, have adverse effects on the power grid, but also have a high failure rate; the variable frequency starting method is generally suitable for speed-regulating motors, but has the disadvantages of high cost and poor electromagnetic compatibility.

[0063] When the motor is disconnected from the power supply, the motor will continue to rotate for a certain period of time due to the existence of rotor inertia and load inertia. The excess rotational torque generated by inertia is not allowed in some applications. Therefore, in some special applications, the motor often needs to take braking measures to eliminate the excess torque generated by inertia and stop the load at the correct position. The braking methods of the motor are generally divided into mechanical braking and electrical braking. When the motor rotor inertia and load inertia are large, neither mechanical braking nor electrical braking can achieve a good effect. In addition, during the operation of the motor, due to the influence of the external environment or the interference of other uncertain factors, the motor often has a short-term overload load, causing the motor speed to drop or stop, resulting in serious heating of the motor or burning of the motor.

[0064] Based on this, the present application provides a motor starting, braking, and torque compensation system and method, which integrates the functions of motor starting, braking, and torque compensation into one system, solves the problem of excessive starting current of high-power motors, reduces the torque generated by the inertia of the motor and load during braking, and compensates for the short-term overload torque deficiency of the motor.

[0065] Specifically, Figure 1 As shown, the motor starting, braking, and torque compensation system provided by the present application includes a hydraulic system part, a rotary actuator part, and a control module. Among them, the hydraulic system part is composed of an accumulator energy storage and release circuit, a clutch control circuit, a clutch control circuit and a brake braking circuit. The accumulator energy storage and release circuit is composed of a fuel tank 1, a relief valve 2, a hydraulic pump-motor 3, a two-position two-way electromagnetic reversing valve 13, a cartridge valve 15, a pressure sensor 14, a stop valve 16, an accumulator 17, and a two-position three-way electromagnetic reversing valve 18 connected in sequence through hydraulic pipelines; the clutch control circuit is composed of a cartridge valve 15, a two-position three-way electromagnetic reversing valve 191, a fuel tank 1, and a single-acting spring return hydraulic cylinder 12 connected in sequence through hydraulic pipelines; the clutch control circuit is composed of a cartridge valve 15, a two-position three-way electromagnetic reversing valve 191, a fuel tank 1, and a single-acting spring return hydraulic cylinder 12 connected in sequence through hydraulic pipelines; the clutch control circuit is composed of a cartridge valve 15, a two-position three-way electromagnetic reversing valve 191, a fuel tank 1, and a single-acting spring return hydraulic cylinder 12 connected in sequence through hydraulic pipelines. The directional valve 192, the oil tank 1, and the single-acting spring return hydraulic cylinder 11 are connected in sequence through hydraulic pipelines; the brake braking circuit is composed of a cartridge valve 15, a two-position three-way electromagnetic reversing valve 193, the oil tank 1, and a hydraulic brake 9 which are connected in sequence through hydraulic pipelines; the rotary actuator part includes: a hydraulic pump-motor 3, a first clutch 41, a first connecting rod 102, a dual-axis three-phase motor 5, a second clutch 42, a second connecting rod 101, a torque sensor 6, a brake disc 7, a speed sensor 8 and a load 20.

[0066] The accumulator energy storage and release circuit includes an oil tank 1, a relief valve 2, a hydraulic pump-motor 3, a two-position two-way electromagnetic reversing valve 13, a cartridge valve 15, a pressure sensor 14, a stop valve 16, an accumulator 17 and a two-position three-way electromagnetic reversing valve 18. The hydraulic pump-motor 3 is a hydraulic motor with a special structure. When the hydraulic oil drives the hydraulic pump-motor 3 to rotate forward, the hydraulic pump-motor 3 is used as a conventional hydraulic motor. When the motive force drives the hydraulic pump-motor 3 to rotate reversely, the hydraulic pump-motor 3 can be used as a hydraulic pump. The relief valve 2 is used to limit the maximum working pressure of the accumulator 17 in the system and plays a safety protection role; the two-position two-way electromagnetic reversing valve 13 is used to control the on-off of the accumulator 17 in the process of storing and releasing hydraulic oil; the cartridge valve 15 and the two-position three-way electromagnetic reversing valve 18 are used in conjunction to control the opening and closing of the accumulator 17, wherein the cartridge valve 15 can also reduce the leakage of hydraulic oil in the accumulator 17. The pressure sensor 14 is used to detect the pressure at the outlet of the accumulator 17 and provide real-time feedback to the control module; the stop valve 16 is used to cut off the connection between the accumulator 17 and the hydraulic system circuit. The stop valve 16 is provided to facilitate the installation, removal, replacement and maintenance of the accumulator 17. Once the accumulator 17 is installed in the hydraulic system, under normal circumstances, the stop valve 16 is in a fully open state; the accumulator 17 is used to store or release hydraulic oil.

[0067] In addition, the accumulator 17 can be a single accumulator or an accumulator group. Using an accumulator group instead of an accumulator can increase the storage of hydraulic energy, reduce the number of starts and stops of the motor and the hydraulic pump-motor, and increase the working time of the accumulator.

[0068] The clutch control circuit includes a cartridge valve 15, a two-position three-way electromagnetic reversing valve 191, an oil tank 1 and a single-acting spring return hydraulic cylinder 12. The two-position three-way electromagnetic reversing valve 191 and the cartridge valve 15 are used together to control the opening and closing of the oil circuit between the accumulator 17 and the single-acting spring return hydraulic cylinder 12; the single-acting spring return hydraulic cylinder 12 can apply force to the first connecting rod 102 to separate or engage the first clutch 41.

[0069] The clutch control circuit 2 includes a cartridge valve 15, a two-position three-way electromagnetic reversing valve 192, an oil tank 1, and a single-acting spring return hydraulic cylinder 11. The two-position three-way electromagnetic reversing valve 192 and the cartridge valve 15 are used together to control the opening and closing of the oil circuit between the accumulator 17 and the single-acting spring return hydraulic cylinder 11; the single-acting spring return hydraulic cylinder 11 can apply force to the second connecting rod 101 to separate or engage the second clutch 42.

[0070] The brake circuit includes a cartridge valve 15, a two-position three-way electromagnetic reversing valve 193, an oil tank 1 and a hydraulic brake 9. The two-position three-way electromagnetic reversing valve 193 and the cartridge valve 15 are used together to control the opening and closing of the oil circuit between the accumulator 17 and the hydraulic brake 9; the hydraulic brake 9 can clamp or release the brake disc 7, thereby achieving braking or non-braking of the load 20.

[0071] The rotary actuator part includes: a hydraulic pump-motor 3, a first clutch 41, a first connecting rod 102, a dual-axis three-phase motor 5, a second clutch 42, a second connecting rod 101, a torque sensor 6, a brake disc 7, a speed sensor 8 and a load 20. The first clutch 41 is used to realize the separation and engagement of the hydraulic pump-motor 3 and the dual-axis three-phase motor 5; the second clutch 42 is used to realize the separation and engagement of the dual-axis three-phase motor 5 and the load 20; the first clutch 41 and the second clutch 42 are in an engaged state when not subjected to the pressure of the first connecting rod 102 and the second connecting rod 101; the dual-axis three-phase motor 5 can be connected to the hydraulic pump-motor 3 and the load 20 respectively through the first clutch 41 and the second clutch 42, and the dual-axis three-phase motor 5 can realize forward and reverse rotation; the torque sensor 6 is installed between the second clutch 42 and the load 20, and is used to detect the torque size of the load 20 and provide real-time feedback to the control module. The brake disc 7 is installed between the second clutch 42 and the load 20, and the brake disc 7 is used in conjunction with the hydraulic brake 9 to realize braking. The speed sensor 8 is installed on the rotating shaft of the load 20 to detect the speed of the load 20 and provide real-time feedback to the control module.

[0072] Among them, the control module can receive feedback signals from the pressure sensor 14 and the torque sensor 6 in the system in real time, the control module can control the on and off of the two-position two-way solenoid reversing valve 13, the two-position three-way solenoid reversing valve 18 and the two-position three-way solenoid reversing valves 191, 192, and 193, and the control module can control the power on, power off, forward rotation, and reverse rotation of the dual-axis three-phase motor 5.

[0073] The control method of the motor starting, braking and torque compensation system is as follows:

[0074] The system is in the following state before normal operation:

[0075] Before the accumulator 17 is installed in the hydraulic system circuit, a certain amount of hydraulic oil should be pre-filled so that the pressure in the accumulator 17 can simultaneously supply the clutch control circuit 1, the clutch control circuit 2 and the brake circuit to perform corresponding actions, and the minimum pressure in the accumulator 17 at this time is assumed to be P1; the stop valve 16 is in a fully open state; the two-position two-way electromagnetic reversing valve 13, the two-position three-way electromagnetic reversing valve 18 and the two-position three-way electromagnetic reversing valves 191, 192, 193 are all not energized and are in the left position; the overflow valve 2 has set the maximum working pressure Pmax of the system; the single-acting spring return hydraulic cylinder 12 pushes the first connecting rod 102 under the action of the return spring to apply a pressure to the first clutch 41, so that the first clutch 41 is in a disengaged state; the single-acting spring return hydraulic cylinder 11 pulls the second connecting rod 101 back under the action of the return spring, and will not generate a force on the second clutch 42, and the second clutch 42 is in an engaged state; when there is no hydraulic pressure on the hydraulic brake 9, the hydraulic brake 9 is separated from the brake disc 7, and there is no braking effect at this time.

[0076] In the system, the process of storing hydraulic energy in the accumulator 17 includes the following steps:

[0077] S1. The control module first controls the two-position three-way electromagnetic reversing valve 18 to be energized and opened, and the cartridge valve 15 is opened at this time. Then the two-position three-way electromagnetic reversing valves 191 and 192 are simultaneously controlled to be energized and opened. At this time, the hydraulic oil in the accumulator 17 flows to the single-acting spring return hydraulic cylinder 12 through the cartridge valve 15 and the two-position three-way electromagnetic reversing valve 191. Under the action of the hydraulic oil, the piston rod of the single-acting spring return hydraulic cylinder 12 is pushed back to the rodless cavity and the first connecting rod 102 is pulled, so that the first clutch 41 is not stressed. At this time, the first clutch 41 is in the engaged state. At the same time, the hydraulic oil in the accumulator 17 also flows to the single-acting spring return hydraulic cylinder 11 through the cartridge valve 15 and the two-position three-way electromagnetic reversing valve 192. Under the action of the hydraulic oil, the piston rod of the single-acting spring return hydraulic cylinder 11 is pushed to extend to the rod cavity and the second connecting rod 101 is pushed to apply a pressure to the second clutch 42, so that the second clutch 42 is in the disengaged state. At this time, the dual-shaft three-phase motor 5 is separated from one side of the load 20 and is engaged with the hydraulic pump-motor 3 , and the dual-shaft three-phase motor 5 is in a light-load state.

[0078] S2. The control module controls the two-position two-way electromagnetic reversing valve 13 to be powered on and turned on. At the same time, the control module controls the double-axis three-phase motor 5 to rotate in the opposite direction, drives the hydraulic pump-motor 3 to rotate in the opposite direction through the first clutch 41, and charges the accumulator 17 with hydraulic oil. At this time, the hydraulic pump-motor 3 is used as a hydraulic pump. When the pressure sensor 14 detects that the pressure at the outlet of the accumulator 17 reaches the set value, the control module first controls the two-position two-way electromagnetic reversing valve 13 to be powered off and closed, and then controls the two-position three-way electromagnetic reversing valve 18 and the two-position three-way electromagnetic reversing valves 191 and 192 to be powered off and closed. At this time, the cartridge valve 15 is also closed due to the closure of the two-position three-way electromagnetic reversing valve 18. At this point, the process of storing hydraulic energy in the accumulator 17 is completed, and it is ready for the next start of the motor and compensation of the motor torque.

[0079] In the system, the process of starting the dual-axis three-phase motor 5 with load is as follows:

[0080] The control module controls the two-position three-way electromagnetic reversing valve 18 to be energized and opened, and the cartridge valve 15 is opened at this time. The control module then controls the two-position three-way electromagnetic reversing valve 191 to be energized and opened, and the hydraulic oil in the accumulator 17 flows to the single-acting spring return hydraulic cylinder 12 through the cartridge valve 15 and the two-position three-way electromagnetic reversing valve 191. Under the action of the hydraulic oil, the piston rod of the single-acting spring return hydraulic cylinder 12 is pushed back to the rodless cavity and the first connecting rod 102 is pulled, so that the first clutch 41 is not stressed, and the first clutch 41 is in the engaged state at this time. Because the two-position three-way electromagnetic reversing valves 192 and 193 are in the de-energized closed state, the second clutch 42 is in the engaged state, and the hydraulic brake 9 is also in the non-braking state. Then the control module controls the two-position two-way electromagnetic reversing valve 13 to be powered on, and the high-pressure hydraulic oil in the accumulator 17 drives the hydraulic pump-motor 3 through the cartridge valve 15 and the two-position two-way electromagnetic reversing valve 13 to drive the dual-axis three-phase motor 5 and the load 20 to rotate forward. At this time, the hydraulic pump-motor 3 is used as a hydraulic motor. When the speed sensor 8 detects that the speed of the load reaches a certain value, the control module simultaneously controls the two-position three-way electromagnetic reversing valve 18, the two-position two-way electromagnetic reversing valve 13 and the two-position three-way electromagnetic reversing valve 191 to be powered off and closed. At this time, the accumulator 17 no longer supplies oil to the hydraulic pump-motor 3 and the single-acting spring return hydraulic cylinder 12, and the hydraulic pump-motor 3 stops rotating. The first clutch 41 is in a disengaged state under the push of the single-acting spring return hydraulic cylinder 12, so that the hydraulic pump-motor 3 and the dual-axis three-phase motor 5 are separated. At the same time, the control module controls the dual-axis three-phase motor 5 to be powered on, so that the dual-axis three-phase motor 5 and the load 20 start at a certain speed, thereby reducing the starting current of the dual-axis three-phase motor 5 when starting with the load 20.

[0081] In the system, the process of the dual-axis three-phase motor 5 starting without load and then connecting to the load 20 is as follows:

[0082] The control module controls the two-position three-way electromagnetic reversing valve 18 to be energized and opened, at which time the cartridge valve 15 is opened, and the control module controls the two-position three-way electromagnetic reversing valve 192 to be energized and opened, and the hydraulic oil in the accumulator 17 flows to the single-acting spring return hydraulic cylinder 11 through the cartridge valve 15 and the two-position three-way electromagnetic reversing valve 192. Under the action of the hydraulic oil, the piston rod of the single-acting spring return hydraulic cylinder 11 is pushed to extend to the rod chamber and push the second connecting rod 101 to apply a pressure to the second clutch 42, so that the second clutch 42 is in a disengaged state. Because the two-position three-way electromagnetic reversing valve 191 is in a de-energized closed state, the first clutch 41 is also in a disengaged state. At this time, that is, when the dual-axis three-phase motor 5 is neither connected to the hydraulic pump-motor 3 nor to the load 20, the control module controls the dual-axis three-phase motor 5 to start rotating in the forward direction. When the speed of the dual-axis three-phase motor 5 is stable, the control module controls the two-position three-way electromagnetic reversing valve 192 and the two-position three-way electromagnetic reversing valve 18 to lose power and close. At this time, the cartridge valve 15 is also closed, and the accumulator 17 no longer supplies oil to the single-acting spring return hydraulic cylinder 11. The second clutch 42 resumes the engagement state under the action of the single-acting spring return hydraulic cylinder 11. At this time, the dual-axis three-phase motor 5 is started without load first, and then the load 20 is connected, so as to reduce the starting current of the dual-axis three-phase motor 5 when working with the load 20.

[0083] In the system, the braking process of the dual-axis three-phase motor 5 with load 20 is as follows:

[0084] When the dual-axis three-phase motor 5 with load 20 needs to brake during operation, the control module controls the two-position three-way solenoid reversing valve 18 to be energized and opened. At this time, the cartridge valve 15 is opened, and the control module controls the two-position three-way solenoid reversing valve 192 to be energized and opened. The hydraulic oil in the accumulator 17 flows to the single-acting spring return hydraulic cylinder 11 through the cartridge valve 15 and the two-position three-way solenoid reversing valve 192. Under the action of the hydraulic oil, the piston rod of the single-acting spring return hydraulic cylinder 11 is pushed to extend into the rod cavity and push the second connecting rod 101 to apply a pressure to the second clutch 42, so that the second clutch 42 is in a disengaged state. When the dual-axis three-phase motor 5 is separated from one side of the load 20, the control module controls the dual-axis three-phase motor 5 to be powered off and stopped, and at the same time, the control module controls the two-position three-way electromagnetic reversing valve 193 to be powered on. Since the two-position three-way electromagnetic reversing valve 18 and the cartridge valve 15 are both open, the hydraulic oil in the accumulator 17 drives the hydraulic brake 9 to clamp the brake disc 7 through the cartridge valve 15 and the two-position three-way electromagnetic reversing valve 193, thereby achieving the braking of the load 20 carried by the dual-axis three-phase motor 5. Since the dual-axis three-phase motor 5 and one side of the load 20 have been separated during braking, the braking process only needs to overcome the torque generated by the load inertia, which is conducive to shortening the braking time, improving the braking efficiency, and eliminating the damage to the structure of the dual-axis three-phase motor 5 caused by the impact caused by the sudden stop of the load 20 during the braking process.

[0085] The system compensates the motor torque in short-term overload operation as follows:

[0086] When the double-shaft three-phase motor 5 drives the load 20 to operate normally, the double-shaft three-phase motor 5 and the hydraulic pump-motor 3 are separated. When the torque sensor 6 detects that the torque on the rotating shaft on one side of the load 20 suddenly increases, and the speed sensor 8 detects that the speed of the load 20 decreases significantly, the control module determines that the double-shaft three-phase motor 5 is in an overloaded operation state. At this time, the control module controls the two-position three-way electromagnetic reversing valve 18 to be energized and opened, and the cartridge valve 15 is opened. The control module then controls the two-position three-way electromagnetic reversing valve 191 to be energized and opened, and the hydraulic oil in the accumulator 17 flows to the single-acting spring return hydraulic cylinder 12 through the cartridge valve 15 and the two-position three-way electromagnetic reversing valve 191. Under the action of the hydraulic oil, the piston rod of the single-acting spring return hydraulic cylinder 12 is pushed back to the rodless cavity and the first connecting rod 102 is pulled, so that the first clutch 41 is not stressed. At this time, the first clutch 41 is in an engaged state. Then the control module controls the two-position two-way solenoid reversing valve 13 to be energized and opened, and the high-pressure hydraulic oil in the accumulator 17 drives the hydraulic pump-motor 3 through the cartridge valve 15 and the two-position two-way solenoid reversing valve 13 to drive the double-axis three-phase motor 5 and the load 20 to rotate in the forward direction, so that the double-axis three-phase motor 5 can smoothly overcome the working condition of insufficient motor output torque due to short-term overload operation.

[0087] After the accumulator 17 releases hydraulic energy once, the control module simultaneously controls the two-position three-way solenoid reversing valve 18, the two-position two-way solenoid reversing valve 13 and the two-position three-way solenoid reversing valve 191 to lose power and close. At this time, the accumulator 17 no longer supplies oil to the hydraulic pump-motor 3 and the single-acting spring return hydraulic cylinder 12, the hydraulic pump-motor 3 stops rotating, and the first clutch 41 is in a disengaged state under the push of the single-acting spring return hydraulic cylinder 12, so that the hydraulic pump-motor 3 and the dual-axis three-phase motor 5 are separated.

[0088] If the accumulator 17 still cannot make the dual-axis three-phase motor 5 cross the overload operation condition after releasing the hydraulic energy once, that is, the torque sensor 6 detects that the torque on the rotating shaft on one side of the load 20 is always large, and the speed sensor 8 detects that the speed of the load 20 is always small, then the control module controls the two-position three-way electromagnetic reversing valve 18 to be energized and opened, and the cartridge valve 15 is opened at this time, and the control module controls the two-position three-way electromagnetic reversing valve 192 to be energized and opened, and the hydraulic oil in the accumulator 17 flows to the single-acting spring return hydraulic cylinder 11 through the cartridge valve 15 and the two-position three-way electromagnetic reversing valve 192. Under the action of the hydraulic oil, the piston rod of the single-acting spring return hydraulic cylinder 11 is pushed to extend to the rod cavity and push the second connecting rod 101 to apply a pressure to the second clutch 42, so that the second clutch 42 is in a disengaged state. Then the control module controls the dual-axis three-phase motor 5 to be powered off and stopped. In this way, the dual-axis three-phase motor 5 and the load 20 are separated, thereby avoiding the risk of the dual-axis three-phase motor 5 stalling due to being unable to drive the load 20 and burning the motor.

[0089] When the system is working, when the pressure sensor 14 detects that the outlet pressure of the accumulator 17 is equal to P1 (P1 is the minimum pressure in the accumulator 17 that can simultaneously supply the clutch control circuit 1, the clutch control circuit 2 and the brake circuit to perform corresponding actions), the control module executes the process of storing hydraulic energy in the accumulator 17. In this way, it is ensured that each time the accumulator 17 releases hydraulic energy, there is still a certain pressure to realize the separation and engagement of the first clutch 41 and the second clutch 42, and to realize the braking of the load 20, thereby ensuring the safety and normal operation of the system.

[0090] The above motor starting, braking, and torque compensation system and method have the following beneficial effects:

[0091] The high-pressure hydraulic oil stored in the accumulator is released to drive the hydraulic motor to drive the motor to rotate. After the motor rotor reaches a certain speed, power is turned on to control the motor to start, thereby achieving the effect of reducing the starting current.

[0092] By releasing the hydraulic oil stored in the accumulator to drive the single-acting spring return hydraulic cylinder, the clutch between the motor and the load is separated. The motor is started without load first, and then the load is connected through the clutch, thereby achieving the effect of reducing the starting current.

[0093] By releasing the hydraulic oil stored in the accumulator to drive the single-acting spring return hydraulic cylinder, the clutch between the motor and the load is separated. The normally operating motor is separated from the load first, and then the power supply of the motor is cut off. At the same time, the hydraulic oil stored in the accumulator is released to drive the brake to clamp the brake disc. In this way, the excess torque generated by the inertia of the motor rotor during braking can be eliminated, so that the braking process only needs to overcome the torque generated by the inertia of the load. This is conducive to shortening the braking time, improving the braking efficiency, and eliminating the damage to the motor structure caused by the impact caused by the sudden stop of the load during the braking process.

[0094] By releasing the high-pressure hydraulic oil stored in the accumulator to drive the hydraulic motor to drive the motor to rotate, the motor torque in short-term overload operation is compensated to avoid burning the motor due to overheating caused by motor shutdown.

[0095] By combining the hydraulic system with the motor equipment, the functions of motor starting, braking and torque compensation are well integrated into one system, which is conducive to the multifunctionality and integration of the system.

[0096] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0097] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A motor control system, characterized in that: It includes a hydraulic system, a rotary actuator and a control module, wherein the hydraulic system is connected to the rotary actuator, and the control module is connected to the hydraulic system and the rotary actuator; the control module is used to control the hydraulic system to drive the rotary actuator to drive the motor to rotate using the hydraulic oil stored in the accumulator, and control the motor to start after the motor rotor reaches a preset speed; wherein, The hydraulic system includes an accumulator energy storage and release control circuit and a second clutch control circuit; the accumulator energy storage and release control circuit is connected to the rotary actuator and the second clutch control circuit, the rotary actuator is connected to the second clutch control circuit, and the control module is connected to the accumulator energy storage and release control circuit and the second clutch control circuit; The accumulator energy storage and release control circuit comprises an oil tank and a cartridge valve, the oil tank is connected to the second clutch control circuit and the rotary actuator, and the cartridge valve is connected to the second clutch control circuit; The second clutch control circuit includes a fourth reversing valve and a second reset hydraulic cylinder, the fourth reversing valve is connected to the control module, the oil tank, the cartridge valve and the second reset hydraulic cylinder, the second reset hydraulic cylinder is connected to the rotary actuator; the fourth reversing valve is a two-position three-way electromagnetic reversing valve; the second reset hydraulic cylinder is a single-acting spring reset hydraulic cylinder.

2. The motor control system according to claim 1, characterized in that: The control module is further used to control the hydraulic system to use the hydraulic oil stored in the accumulator to drive the motor to separate from the load, and to connect the motor to the load after starting the motor without load.

3. The motor control system according to claim 1, characterized in that: The control module is also used to control the hydraulic system to use the hydraulic oil stored in the accumulator to drive the motor to separate from the load, then cut off the power supply of the motor and clamp the brake disc during braking.

4. The motor control system according to claim 1, characterized in that: The control module is also used to control the hydraulic system to use the hydraulic oil stored in the accumulator to compensate for the motor torque in short-term overload operation.

5. The motor control system according to any one of claims 1 to 4, characterized in that: The hydraulic system includes a first clutch control circuit and a brake control circuit; the accumulator energy storage and release control circuit connects the first clutch control circuit and the brake control circuit, the rotary actuator connects the first clutch control circuit and the brake control circuit, and the control module connects the first clutch control circuit and the brake control circuit.

6. The motor control system according to claim 5, characterized in that: The accumulator energy storage and release control circuit includes a first reversing valve, a pressure sensor, an accumulator and a second reversing valve; the oil tank is connected to the first reversing valve, the second reversing valve, the first clutch control circuit and the brake control circuit; the cartridge valve is connected to the first reversing valve, the second reversing valve, the accumulator, the first clutch control circuit and the brake control circuit; the pressure sensor is connected to the accumulator and the control module; the control module is connected to the first reversing valve and the second reversing valve; the first reversing valve is a two-position two-way electromagnetic reversing valve, and the second reversing valve is a two-position three-way electromagnetic reversing valve.

7. The motor control system according to claim 6, characterized in that: The first clutch control circuit includes a third reversing valve and a first reset hydraulic cylinder, the third reversing valve is connected to the control module, the oil tank, the cartridge valve and the first reset hydraulic cylinder, the first reset hydraulic cylinder is connected to the rotary actuator; the third reversing valve is a two-position three-way electromagnetic reversing valve; the first reset hydraulic cylinder is a single-acting spring reset hydraulic cylinder.

8. The motor control system according to claim 6, characterized in that: The brake control circuit includes a fifth reversing valve and a hydraulic brake. The fifth reversing valve is connected to the control module, the oil tank, the cartridge valve and the hydraulic brake. The hydraulic brake is connected to the rotary actuator. The fifth reversing valve is a two-position three-way electromagnetic reversing valve.

9. The motor control system according to claim 6, characterized in that: The rotary actuator includes a hydraulic pump-motor, a first clutch, a first connecting rod, a motor, a second clutch, a second connecting rod, a torque sensor, a brake disc and a speed sensor; the hydraulic pump-motor is connected to the oil tank, the first reversing valve and the first clutch, the first clutch is connected to the first connecting rod and the motor, the first connecting rod is connected to the first clutch control circuit, the motor is connected to the second clutch and the control module, the second clutch is connected to the second connecting rod and the torque sensor, the second connecting rod is connected to the second clutch control circuit, the torque sensor is connected to the control module and the brake disc, the brake disc is connected to the brake control circuit and the speed sensor, and the speed sensor is connected to the control module and the load; the motor is a dual-axis three-phase motor.

10. A motor control method, characterized in that: Based on the motor control system according to any one of claims 1 to 9, the method comprises: The control module controls the hydraulic system to utilize the hydraulic oil stored in the accumulator to drive the rotary actuator to drive the motor to rotate, and controls the motor to start after the motor rotor reaches a preset speed.

11. The motor control method according to claim 10, characterized in that: The process of starting the motor with load includes the following steps: The control module controls the second reversing valve to be powered on and the cartridge valve to be opened, and the control module controls the third reversing valve to be powered on, and the hydraulic oil in the accumulator flows to the first reset hydraulic cylinder through the cartridge valve and the third reversing valve. Under the action of the hydraulic oil, the piston rod of the first reset hydraulic cylinder is pushed back to the rodless cavity and the first connecting rod is pulled, so that the first clutch is not stressed. At this time, the first clutch is in an engaged state; the fourth reversing valve and the fifth reversing valve are in a power-off closed state, the second clutch is in an engaged state, and the hydraulic brake is also in an unbraked state; The control module controls the first reversing valve to be powered on, and the high-pressure hydraulic oil in the accumulator drives the hydraulic pump-motor through the cartridge valve and the first reversing valve to drive the motor and the load to rotate in the forward direction, and the hydraulic pump-motor is used as a hydraulic motor; when the speed sensor detects that the speed of the load reaches the preset value, the control module simultaneously controls the second reversing valve, the first reversing valve and the third reversing valve to lose power and close, at which time the accumulator no longer supplies oil to the hydraulic pump-motor and the first reset hydraulic cylinder, the hydraulic pump-motor stops rotating, and the first clutch is in a disengaged state under the push of the first reset hydraulic cylinder, so that the hydraulic pump-motor and the motor are separated; at the same time, the control module controls the motor to be powered on, so that the motor and the load are started at a rotating speed.

12. The motor control method according to claim 10, characterized in that: The process of starting the motor without load and then connecting the load includes the following steps: The control module controls the second reversing valve to be powered on, at which time the cartridge valve is opened, and the control module then controls the fourth reversing valve to be powered on, and the hydraulic oil in the accumulator flows to the second reset hydraulic cylinder through the cartridge valve and the fourth reversing valve. Under the action of the hydraulic oil, the piston rod of the second reset hydraulic cylinder is pushed to extend to the rod chamber and push the second connecting rod to apply pressure to the second clutch, so that the second clutch is in a disengaged state; the third reversing valve is in a power-off closed state, and the first clutch is also in a disengaged state; when the motor is neither connected to the hydraulic pump-motor nor to the load, the control module controls the motor to start in the forward direction, and when the speed of the motor is stable, the control module controls the fourth reversing valve and the second reversing valve to be powered off and closed, at which time the cartridge valve is closed, and the accumulator no longer supplies oil to the second reset hydraulic cylinder, and the second clutch resumes the engaged state under the action of the second reset hydraulic cylinder.

13. The motor control method according to claim 10, characterized in that: The motor load braking process includes the following steps: When the motor needs to brake under load during operation, the control module controls the second reversing valve to be energized and opened, at which time the cartridge valve is opened, and the control module controls the fourth reversing valve to be energized and opened, and the hydraulic oil in the accumulator flows to the second reset hydraulic cylinder through the cartridge valve and the fourth reversing valve. Under the action of the hydraulic oil, the piston rod of the second reset hydraulic cylinder is pushed to extend to the rod chamber and the second connecting rod is pushed to apply pressure to the second clutch, so that the second clutch is in a disengaged state; When the motor is separated from one side of the load, the control module controls the motor to be powered off and stop, and at the same time, the control module controls the fifth reversing valve to be powered on and opened. Since the second reversing valve and the cartridge valve are both opened, the hydraulic oil in the accumulator drives the hydraulic brake through the cartridge valve and the fifth reversing valve to clamp the brake disc.

14. The motor control method according to claim 10, characterized in that: The process of compensating the motor torque during short-term overload operation includes the following steps: When the torque sensor detects that the torque on the rotating shaft on one side of the load increases, and the speed sensor detects that the speed of the load decreases, the control module determines that the motor is in an overloaded state; the control module controls the second reversing valve to be energized and opened, and the cartridge valve is opened. The control module then controls the third reversing valve to be energized and opened, and the hydraulic oil in the accumulator flows to the first reset hydraulic cylinder through the cartridge valve and the third reversing valve. Under the action of the hydraulic oil, the piston rod of the first reset hydraulic cylinder is pushed back to the rodless chamber and the first connecting rod is pulled, so that the first clutch is not subjected to force. At this time, the first clutch is in an engaged state; The control module controls the first reversing valve to be energized and opened, and the high-pressure hydraulic oil in the accumulator drives the hydraulic pump-motor through the cartridge valve and the first reversing valve to drive the motor and the load to rotate in the forward direction, so that the motor can smoothly cross the working condition where the motor output torque is insufficient due to short-term overload operation; After the accumulator releases the hydraulic energy once, the control module simultaneously controls the second reversing valve, the first reversing valve and the third reversing valve to lose power and close, the accumulator no longer supplies oil to the hydraulic pump-motor and the first reset hydraulic cylinder, the hydraulic pump-motor stops rotating, and the first clutch is in a disengaged state under the push of the first reset hydraulic cylinder, so that the hydraulic pump-motor and the motor are separated; If the accumulator still cannot enable the motor to overcome the overload operating condition after releasing the hydraulic energy once, the control module will control the second reversing valve to be energized and opened. At this time, the cartridge valve will open, and the control module will then control the fourth reversing valve to be energized and opened. The hydraulic oil in the accumulator will flow to the second reset hydraulic cylinder through the cartridge valve and the fourth reversing valve. Under the action of the hydraulic oil, the piston rod of the second reset hydraulic cylinder will be pushed to extend into the rod chamber and the second connecting rod will be pushed to apply pressure to the second clutch, so that the second clutch is in a disengaged state. The control module will then control the motor to cut off the power and stop.

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