阅读说明：本技术 一种新能源管片拼装机电控方法及系统 (Electric control method and system for new energy segment erector ) 是由 刘瑜君 于 2021-09-17 设计创作，主要内容包括：本发明提供了一种新能源管片拼装机电控系统,包括：拼装侧电控箱,所述拼装侧电控箱安装在拼装机大臂处,所述拼装侧电控箱通过无线通讯与外界控制设备进行信息传递；液压系统,包括液压回路与液压油泵,所述拼装机大臂活动端均设有单独的液压回路,并通过液压驱动拼装机大臂活动；电池组；所述拼装侧电控箱通过信号电缆控制电磁阀供电,所述液压油泵、拼装侧电控箱以及电池组与拼装机同步回转。一种新能源管片拼装机电控方法,包括以下步骤：发出启动指令；为电控系统供电；为液压回路供油；电磁阀供电；控制拼装机大臂执行预设动作拼装管片。能够达到拼装机回转不受限、可实现任意角度及圈数回转、使得拼装作业更方便的效果。(The invention provides an electric control system of a new energy segment erector, which comprises: the assembling side electric cabinet is arranged at the position of a large arm of the assembling machine and is in information transmission with external control equipment through wireless communication; the hydraulic system comprises hydraulic loops and hydraulic oil pumps, and the movable ends of the large arms of the erector are provided with the independent hydraulic loops and drive the large arms of the erector to move through hydraulic pressure; a battery pack; the assembling side electric control box controls the electromagnetic valve to supply power through a signal cable, and the hydraulic oil pump, the assembling side electric control box and the battery pack synchronously rotate with the assembling machine. An electric control method of a new energy segment erector comprises the following steps: sending a starting instruction; supplying power to the electric control system; supplying oil to the hydraulic circuit; the electromagnetic valve supplies power; and controlling a large arm of the splicing machine to execute a preset action to splice the duct pieces. The effect that the rotation of the splicing machine is not limited, the rotation at any angle and number of turns can be realized, and the splicing operation is more convenient can be achieved.)

1. The utility model provides an electromechanical system is assembled to new forms of energy section of jurisdiction which characterized in that: new forms of energy section of jurisdiction erector electrical system includes:

the assembling side electric cabinet is arranged at the position of a large arm of the assembling machine and is in information transmission with external control equipment through wireless communication;

the hydraulic system comprises hydraulic loops and hydraulic oil pumps, wherein the movable ends of the large arms of the splicing machine are respectively provided with an independent hydraulic loop and drive the large arms of the splicing machine to move through hydraulic pressure, the hydraulic oil pumps are communicated with the hydraulic loops, electromagnetic valves are arranged at the communication positions of the hydraulic oil pumps and the hydraulic loops, and the hydraulic oil pumps output hydraulic oil for the hydraulic loops;

the battery pack is used for supplying power to the hydraulic pump, the assembling side electric cabinet and the electromagnetic valve;

the assembling side electric control box controls the electromagnetic valve to supply power through a signal cable, and the hydraulic oil pump, the assembling side electric control box and the battery pack synchronously rotate with the assembling machine.

2. The electric control system of the new energy segment assembling machine according to claim 1, characterized in that: the electric control system of the new energy segment erector further comprises an erector remote controller and a platform side control box, wherein the erector remote controller transmits signals to the platform side control box through wireless communication; the platform side control box is installed on a shield machine platform and carries out information transmission with the assembling side electric control box and a shield machine main system through wireless communication.

3. The electric control system of the new energy segment assembling machine according to claim 2, characterized in that: the assembling side electric cabinet comprises a battery management system, and the battery management system receives a control signal of the platform side control box to control the power supply of the battery pack, monitors the state of the battery pack and sends the state of the battery pack to the platform side control box.

4. The electric control system of the new energy segment assembling machine according to claim 3, characterized in that: the hydraulic system further comprises a hydraulic oil tank, a motor and a hydraulic switch, the hydraulic oil tank is arranged on the assembling machine, the motor and the hydraulic oil pump are arranged on the hydraulic oil tank, the motor drives the hydraulic oil pump to operate, and the hydraulic switch is arranged on an output pipeline of the hydraulic oil pump and sends hydraulic information detected by the hydraulic oil pump to the assembling side electric cabinet.

5. The electric control system of the new energy segment assembling machine according to claim 4, characterized in that: the assembling side electric cabinet also comprises an inverter, a driver and a signal converter, wherein the inverter converts direct current of the battery pack into alternating current and then supplies power to the electromagnetic valve, the driver converts the direct current of the battery pack into alternating current with adjustable voltage to supply power to the motor, and the signal converter is used for converting signals received by the assembling side electric cabinet and output signals.

6. A new energy segment assembling machine electric control method is characterized in that: the electric control method of the new energy segment erector comprises the following steps:

the main system of the shield machine sends a starting instruction to the electric control box at the assembling side through the control box at the platform side;

the battery pack supplies power to the electric control system after the assembling side electric control box receives the starting instruction;

the hydraulic oil pump is driven by the motor to supply oil to the hydraulic loop;

the assembling side electric cabinet controls electromagnetic valves on all the hydraulic circuits to supply power;

the power provided by the hydraulic loop controls the large arm of the erector to execute preset actions to assemble the duct piece.

7. The electric control method of the new energy segment assembling machine according to claim 6, characterized in that: after the assembling side electric cabinet receives the starting instruction, the battery pack starts to supply power after self-checking is carried out on the battery pack through the battery management system, and the battery management system continuously monitors the state of the battery pack and feeds the state back to the assembling side electric cabinet in the power supply process of the battery pack.

8. The electric control method of the new energy segment assembling machine according to claim 6, characterized in that: the battery pack converts direct current of the battery pack into alternating current with adjustable voltage through a driver in the electric cabinet to drive the hydraulic oil pump, and the hydraulic oil pump pumps hydraulic oil in the hydraulic oil tank to supply oil to the hydraulic loop.

9. The electric control method of the new energy segment assembling machine according to claim 6, characterized in that: and an inverter in the assembled side electric cabinet converts direct current of the battery pack into alternating current to control power supply of the electromagnetic valves on each hydraulic loop.

Technical Field

The invention belongs to the technical field of tunnel excavation equipment, and particularly relates to an electric control method and system for a segment assembling machine of a shield tunneling machine.

Background

The shield machine is a special engineering machine for tunneling, integrates light, mechanical, electrical, hydraulic, sensing and information technologies into a whole, has the functions of excavating and cutting soil bodies, conveying muck, assembling tunnel lining, measuring, guiding, correcting deviation and the like, relates to multiple subject technologies such as geology, construction, machinery, mechanics, hydraulic pressure, electricity, control, measurement and the like, and is widely applied to tunnel engineering such as subways, railways, highways, municipal administration, hydropower and the like.

As an important component of a shield machine, the segment erector is used for quickly and accurately installing segments on the surface of a tunnel which is just excavated so as to support the surface of the tunnel and prevent the penetration of underground water and soil and the settlement of the earth surface, and the segments bear the advancing counter force of the shield. Seven actions (lifting, translation and rotation of the segment, pitching, rolling and deflection of the clamping mechanism and locking of the segment) of the segment erector are completed by a hydraulic motor and a hydraulic oil cylinder of a hydraulic system.

The existing segment erector needs to adopt a cable reel to supply power to a hydraulic oil pump driving motor and a hydraulic electromagnetic valve, the cable rotates along with the rotating operation of the segment erector, the cable reel is easy to wear and needs to be replaced regularly after long-term use, the number of cables in the reel is large, and the cable is inconvenient to overhaul once a system line fails. The rotation angle of the assembling machine is limited, generally ranges from-220 degrees to +220 degrees, free rotation at any angle and turns cannot be realized, and the operation is inconvenient. The oil pressure of the hydraulic system is ensured by manually controlling the starting and stopping of the oil pump, the labor intensity is high, and the working efficiency is low.

Disclosure of Invention

In view of the defects of the existing segment splicing, the invention provides the electric control method and the electric control system for the new energy segment splicing machine, which can achieve the effects that the rotation of the splicing machine is not limited, the rotation at any angle and number of turns can be realized, and the splicing operation is more convenient.

In order to achieve the purpose, the invention adopts the following technical scheme:

the utility model provides a new forms of energy section of jurisdiction erector electrical system, new forms of energy section of jurisdiction erector electrical system includes:

the assembling side electric cabinet is arranged at the position of a large arm of the assembling machine and is in information transmission with external control equipment through wireless communication;

the hydraulic system comprises hydraulic loops and hydraulic oil pumps, wherein the movable ends of the large arms of the splicing machine are respectively provided with an independent hydraulic loop and drive the large arms of the splicing machine to move through hydraulic pressure, the hydraulic oil pumps are communicated with the hydraulic loops, electromagnetic valves are arranged at the communication positions of the hydraulic oil pumps and the hydraulic loops, and the hydraulic oil pumps output hydraulic oil for the hydraulic loops;

the battery pack is used for supplying power to the hydraulic pump, the assembling side electric cabinet and the electromagnetic valve;

the assembling side electric control box controls the electromagnetic valve to supply power through a signal cable, and the hydraulic oil pump, the assembling side electric control box and the battery pack synchronously rotate with the assembling machine.

According to one aspect of the invention, the electric control system of the new energy segment erector further comprises an erector remote controller and a platform side control box, wherein the erector remote controller transmits signals to the platform side control box through wireless communication; the platform side control box is installed on a shield machine platform and carries out information transmission with the assembling side electric control box and a shield machine main system through wireless communication.

According to one aspect of the invention, the assembly side electric cabinet comprises a battery management system, and the battery management system receives a control signal of the platform side control box to control the battery pack to supply power, monitors the battery pack state and sends the battery pack state to the platform side control box.

According to one aspect of the invention, the hydraulic system further comprises a hydraulic oil tank, a motor and a hydraulic switch, the hydraulic oil tank is arranged on the assembling machine, the motor and a hydraulic oil pump are arranged on the hydraulic oil tank, the motor drives the hydraulic oil pump to operate, and the hydraulic switch is arranged on an output pipeline of the hydraulic oil pump and sends hydraulic information detected by the hydraulic oil pump to the electric control box on the assembling side.

According to one aspect of the invention, the electric control box on the splicing side further comprises an inverter, a driver and a signal converter, wherein the inverter converts direct current of the battery pack into alternating current and then supplies power to the electromagnetic valve, the driver converts the direct current of the battery pack into alternating current with adjustable voltage to supply power to the motor, and the signal converter is used for converting signals received by the electric control box on the splicing side and converting output signals.

An electric control method of a new energy segment erector comprises the following steps:

the main system of the shield machine sends a starting instruction to the electric control box at the assembling side through the control box at the platform side;

the battery pack supplies power to the electric control system after the assembling side electric control box receives the starting instruction;

the hydraulic oil pump is driven by the motor to supply oil to the hydraulic loop;

the assembling side electric cabinet controls electromagnetic valves on all the hydraulic circuits to supply power;

the power provided by the hydraulic loop controls the large arm of the erector to execute preset actions to assemble the duct piece.

According to one aspect of the invention, after the assembling side electric cabinet receives the starting instruction, the battery management system performs self-check on the battery pack and then enables the battery pack to start to supply power, and the battery management system continuously monitors the state of the battery pack and feeds the state back to the assembling side electric cabinet in the power supply process of the battery pack.

According to one aspect of the invention, the battery pack converts direct current of the battery pack into alternating current with adjustable voltage through a driver in the electric cabinet to drive a hydraulic oil pump, and the hydraulic oil pump pumps hydraulic oil in a hydraulic oil tank to supply oil to a hydraulic circuit.

According to one aspect of the invention, an inverter in the electric cabinet on the assembling side converts direct current of the battery pack into alternating current to control power supply of the electromagnetic valves on the hydraulic circuits.

The implementation of the invention has the advantages that:

the invention provides an electric control system of a new energy segment erector, which comprises: the assembling side electric cabinet is arranged at the position of a large arm of the assembling machine and is in information transmission with external control equipment through wireless communication; the hydraulic system comprises hydraulic loops and hydraulic oil pumps, wherein the movable ends of the large arms of the splicing machine are respectively provided with an independent hydraulic loop and drive the large arms of the splicing machine to move through hydraulic pressure, the hydraulic oil pumps are communicated with the hydraulic loops, electromagnetic valves are arranged at the communication positions of the hydraulic oil pumps and the hydraulic loops, and the hydraulic oil pumps output hydraulic oil for the hydraulic loops; the battery pack is used for supplying power to the hydraulic pump, the assembling side electric cabinet and the electromagnetic valve; the assembling side electric control box controls the electromagnetic valve to supply power through a signal cable, and the hydraulic oil pump, the assembling side electric control box and the battery pack synchronously rotate with the assembling machine. An electric control method of a new energy segment erector comprises the following steps: the main system of the shield machine sends a starting instruction to the electric control box at the assembling side through the control box at the platform side; the battery pack supplies power to the electric control system after the assembling side electric control box receives the starting instruction; the hydraulic oil pump is driven by the motor to supply oil to the hydraulic loop; the assembling side electric cabinet controls electromagnetic valves on all the hydraulic circuits to supply power; the power provided by the hydraulic loop controls the large arm of the erector to execute preset actions to assemble the duct piece. The effect that the rotation of the splicing machine is not limited, the rotation at any angle and number of turns can be realized, and the splicing operation is more convenient can be achieved.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is an appearance schematic diagram of an electric control system of a new energy segment assembling machine according to the invention;

FIG. 2 is a schematic structural diagram of an electric control system of the new energy segment assembling machine according to the invention;

fig. 3 is a three-dimensional view of an electric control method and system of a new energy segment erector according to the present invention.

Description of reference numerals: 1. a hydraulic oil tank; 2. a balancing weight; 3. a first battery pack; 4. a second battery pack; 5. an electric motor; 6. a hydraulic oil pump; 7. assembling a side electric cabinet; 8. a shield machine platform; 9. a charger; 10. a platform side control box; 11. a duct piece; 12. a splicing machine main body; 13. a remote controller of the assembling machine; 14. and (4) a hydraulic switch.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

As shown in fig. 1, 2 and 3, the electric control system of the new energy segment erector comprises:

the assembling side electric cabinet 7 is arranged at the position of a large arm of the assembling machine, and the assembling side electric cabinet 7 is in information transmission with external control equipment through wireless communication;

the hydraulic system comprises hydraulic loops and hydraulic oil pumps 6, the movable ends of the large arms of the splicing machine are respectively provided with an independent hydraulic loop and drive the large arms of the splicing machine to move through hydraulic pressure, the hydraulic oil pumps 6 are communicated with the hydraulic loops, electromagnetic valves are arranged at the positions where the hydraulic oil pumps 6 are communicated with the hydraulic loops and are communicated with the hydraulic loops, and hydraulic oil is output to the hydraulic loops;

the battery pack is used for supplying power to the hydraulic pump, the assembling side electric cabinet 7 and the electromagnetic valve;

the assembling side electric cabinet 7 controls the electromagnetic valve to supply power through a signal cable, and the hydraulic oil pump 6, the assembling side electric cabinet 7 and the battery pack synchronously rotate with the assembling machine.

According to one aspect of the invention, the electric control system of the new energy segment erector further comprises the erector remote controller 13 and the platform side control box 10, wherein the erector remote controller 13 transmits signals to the platform side control box 10 through wireless communication; the platform side control box 10 is installed on a platform of the shield tunneling machine, and the platform side control box 10 carries out information transmission with the assembling side electric control box 7 and a shield tunneling machine main system through wireless communication.

According to one aspect of the present invention, the assembly side electric cabinet 7 includes a battery management system, which receives the control signal from the platform side control box 10 to control the battery pack to supply power, monitors the battery pack status, and sends the battery pack status to the platform side control box 10.

According to one aspect of the invention, the hydraulic system further comprises a hydraulic oil tank 1, a motor 5 and a hydraulic switch 14, wherein the hydraulic oil tank 1 is arranged on the assembling machine, the motor 5 and a hydraulic oil pump 6 are arranged on the hydraulic oil tank 1, the motor 5 drives the hydraulic oil pump 6 to operate, and the hydraulic switch 14 is arranged on an output pipeline of the hydraulic oil pump 6 and sends hydraulic information detected by the hydraulic oil pump to the assembling side electric cabinet 7.

According to an aspect of the present invention, the assembly-side electric cabinet 7 further includes an inverter, a driver and a signal converter, the inverter converts the direct current of the battery pack into an alternating current and then supplies power to the electromagnetic valve, the driver converts the direct current of the battery pack into an alternating current with adjustable voltage to supply power to the motor 5, and the signal converter is used for converting the received signal and the output signal of the assembly-side electric cabinet 7.

The new energy battery packs 3 and 4 adopt two groups of super capacitors, one for use and the other for standby.

The motor 5 adopts a three-phase asynchronous motor.

The assembling side electric cabinet 7 comprises a BMS battery management system, a PLC, an inverter, a driver, an RS485/wifi network converter and the like.

The platform side control box 10 comprises a PLC, an RS485/wifi network converter, a Bluetooth I/O module and the like.

The new energy battery packs 3 and 4 are connected with the assembling side electric cabinet 7 through power cables and communication cables. The assembling side electric cabinet 7 is connected with the motor 5 and each hydraulic loop electromagnetic valve through power cables. The assembling side electric cabinet 7 and the platform side control box 10 are in wireless communication through an RS485/wifi network converter. The platform side control box 10 is connected with a PLC of a main system of a driving cab of the shield tunneling machine through a CC-link or an Ethernet, so that long-distance signal transmission is stable, and the receiving and control of a main system of the shield tunneling machine on data are guaranteed so as to cooperate with the normal operation of the shield tunneling machine.

An electric control method of a new energy segment erector comprises the following steps:

s1, the main system of the shield machine sends a starting instruction to the electric control box at the assembling side through the control box at the platform side;

s2, the battery pack supplies power to the electric control system after the electric control box on the assembling side receives the starting instruction;

after the assembling side electric cabinet receives the starting instruction, the battery pack starts to supply power after self-checking is carried out on the battery pack through the battery management system, and the battery management system continuously monitors the state of the battery pack and feeds the state back to the assembling side electric cabinet in the power supply process of the battery pack.

The electric control system is used for the power-on (power-off) process: the shield machine enters (exits) an assembling mode, a main system PLC sends a starting (stopping and resetting) instruction to a platform side control box 10 through a CC-link or an Ethernet, the platform side control box 10 receives the instruction and then transmits the instruction to an assembling side electric control box 7, the PLC of the assembling side electric control box 7 sends a power-on instruction to a BMS battery management system through a communication cable after receiving the instruction, the BMS battery management system closes (disconnects) a power-on switch of the new energy battery pack 3&4 after the initialization self-detection is completed to power on (power off), and the whole assembling system is powered on (power off).

The BMS battery management system performs overall control of the battery, including voltage balancing, SOC control, charge and discharge control, protection, fault feedback, and the like.

The BMS battery management system feeds battery state data including SOC, voltage, current, fault codes and the like back to the assembling side electric cabinet 7, the assembling side electric cabinet 7 feeds back to the platform side control box 10 through wireless communication, and finally the platform side control box 10 feeds back to a main system PLC through CC-l ink or Ethernet.

S3, the hydraulic oil pump is driven by the motor to supply oil for the hydraulic loop;

the battery pack converts direct current of the battery pack into alternating current with adjustable voltage through a driver in the electric cabinet to drive the hydraulic oil pump, and the hydraulic oil pump pumps hydraulic oil in the hydraulic oil tank to supply oil to the hydraulic loop.

The hydraulic oil pump starts and stops the process: the assembly sends a starting signal to the assembly side electric cabinet 7. Meanwhile, the pressure switch 14 feeds back a pressure signal to the PLC of the assembling side electric cabinet 7 through a signal cable, and the PLC compares the feedback pressure with a design pressure, determines and sends a start, stop and reset signal to the driver.

The driver converts direct current of the new energy battery packs 3 and 4 into alternating current with adjustable frequency and voltage, supplies power to the motor 5, sets acceleration and deceleration time of the driver, and realizes variable-frequency starting and stopping of the motor 5.

The electric motor 5 drives the hydraulic oil pump 6 to rotate so as to provide oil with certain pressure for the hydraulic system. The driver feeds back the operation and fault signals of the driver to the assembly side electric cabinet 7 through a signal cable, the assembly side electric cabinet 7 feeds back the operation, fault signals and pressure signals of the driver to the platform side control box 10 through wireless communication, and finally the platform side control box 10 feeds back the operation, fault signals and pressure signals to the main system PLC through CC-l ink or Ethernet.

S4, controlling the electromagnetic valves on the hydraulic circuits to supply power by the assembling side electric cabinet;

and an inverter in the assembled side electric cabinet converts direct current of the battery pack into alternating current to control power supply of the electromagnetic valves on each hydraulic loop.

And S5, controlling the large arm of the splicing machine to execute preset actions to splice the duct piece through power provided by a hydraulic circuit.

Duct piece assembling action process: after the assembling machine system is powered on, the inverter converts the direct current of the new energy battery packs 3 and 4 into alternating current, and the alternating current is controlled by the PLC of the assembling side electric cabinet 7 to supply power to the electromagnetic valves of the hydraulic loops. The remote controller 13 of the erector sends an action instruction (such as large arm extension) through Bluetooth, the Bluetooth module of the platform side control box 10 receives the action instruction (such as large arm extension) and transmits the action instruction to the PLC of the platform side control box 10 through a signal cable for processing, the platform side control box 10 transmits the action instruction (such as large arm extension) to the assembling side electric control box 7 through wireless communication, the PLC of the assembling side electric control box 7 sends the action instruction to enable the large arm extension relay to be powered on, so that the large arm extension hydraulic circuit electromagnetic valve is powered on to act, the hydraulic oil cylinder extends out, and the large arm extension action of the erector is realized.

The action processes of the erector such as big arm contraction, small foot extension and small foot contraction are the same as above. After the new energy power supply mode is adopted, the rotation of the assembling machine is not limited, and the rotation at any angle and number of turns can be realized, so that the assembling operation is more convenient.

The implementation of the invention has the advantages that:

the invention provides an electric control system of a new energy segment erector, which comprises: the assembling side electric cabinet is arranged at the position of a large arm of the assembling machine and is in information transmission with external control equipment through wireless communication; the hydraulic system comprises hydraulic loops and hydraulic oil pumps, wherein the movable ends of the large arms of the splicing machine are respectively provided with an independent hydraulic loop and drive the large arms of the splicing machine to move through hydraulic pressure, the hydraulic oil pumps are communicated with the hydraulic loops, electromagnetic valves are arranged at the communication positions of the hydraulic oil pumps and the hydraulic loops, and the hydraulic oil pumps output hydraulic oil for the hydraulic loops; the battery pack is used for supplying power to the hydraulic pump, the assembling side electric cabinet and the electromagnetic valve; the assembling side electric control box controls the electromagnetic valve to supply power through a signal cable, and the hydraulic oil pump, the assembling side electric control box and the battery pack synchronously rotate with the assembling machine. An electric control method of a new energy segment erector comprises the following steps: the main system of the shield machine sends a starting instruction to the electric control box at the assembling side through the control box at the platform side; the battery pack supplies power to the electric control system after the assembling side electric control box receives the starting instruction; the hydraulic oil pump is driven by the motor to supply oil to the hydraulic loop; the assembling side electric cabinet controls electromagnetic valves on all the hydraulic circuits to supply power; the power provided by the hydraulic loop controls the large arm of the erector to execute preset actions to assemble the duct piece. The effect that the rotation of the splicing machine is not limited, the rotation at any angle and number of turns can be realized, and the splicing operation is more convenient can be achieved. And the power supply, control and signal transmission of the splicing machine are realized by a brand new mode. Adopt new forms of energy group battery power supply to need not cable reel, the fault rate is low, it is convenient to overhaul. The new energy battery pack adopts a super capacitor, is safe and environment-friendly, and meets the requirements of short charging time under the condition of large-multiplying-power charging and discharging, and long service life of more than 10 ten thousand charging cycles. The rotation of the assembling machine is not limited, and the assembling machine can rotate at any angle and number of turns, so that the assembling operation is more convenient. The start and stop of the hydraulic oil pump are completely automatically controlled, manual operation intervention is not needed, the efficiency is improved, and the labor intensity is reduced. The motor is started and stopped at variable frequency, so that the motor is protected, and energy is saved.

The above description is only an embodiment of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention disclosed herein are intended to be covered by the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.