Servo permanent magnet electric direct drive system for unattended mine hoist

Abstract

The invention discloses an unattended servo permanent magnet electric direct drive system for a mine hoist, which belongs to the technical field of mine hoists and comprises a servo permanent magnet direct drive motor system, a loading system, an unloading system, a braking safety monitoring system and a hoisting main control system. The loading system and the unloading system can control loading and unloading of materials in a mine hoist of the system, the hoisting main control system is connected with the servo permanent magnet direct drive motor system, the loading system, the unloading system and the braking safety monitoring system through signal lines, unmanned and remote operation is achieved, work is completed through one key, and the working efficiency is improved. On-site safe operation parameters are intelligently adjusted through the control system, meanwhile, various potential safety hazards and fault parameters are predicted in advance and sent to related personnel in the form of real-time information, the safety and reliability of the system are greatly improved, and energy conservation and consumption reduction are achieved through the servo permanent magnet direct drive motor.

Description

Technical Field

[0001] The present invention relates to a servo permanent magnet direct drive system for an unattended mine hoist, belonging to the technical field of mine hoists. Background Art

[0002] A mine hoist, also known as a mine elevator or a winch, is a large-scale lifting mechanical device. It is installed on the ground and drives the hoist to run along a vertical shaft or a ramp through a steel wire rope to complete the conveying task. Mine hoists are mainly used to lift materials such as coal, ore, and gangue in vertical shafts and inclined shafts, as well as to lift personnel, lower materials, tools, and equipment. It is a very important conveying tool in the project of transporting people and materials in mines.

[0003] The traditional power drive system of a mine hoist consists of a main power drive system, a loading system, an unloading system, and a hoisting control system. The hoisting control system only controls the main power drive system, and operates independently from the loading system and the unloading system. There is no automatic information transfer between the loading system, the unloading system, and the hoisting control system, and information needs to be sent manually. The loading system requires independent workers to operate the vehicle underground. After the loading system operator finishes the operation, he sends a signal to the hoisting control system by ringing a bell, making a phone call, or just sending a loading completion message. After the hoist operator sees that the loading is completed, he then starts the hoist to rise, and automatically unloads coal at the top. The coal unloading process cannot be controlled. After the hoist operator estimates a certain time, regardless of whether the coal unloading is successful or not, he lowers the hoist. The material level information of the underground storage bin and the material level information of the above-ground storage bin often need to be manually confirmed, resulting in problems such as high labor intensity, low automation level, and poor working environment. The braking system of the traditional mine hoist is a relatively independent unit. After normal debugging, the main parameters such as the braking oil pressure and the braking state are transmitted to the hoisting control system, and whether the parameters are abnormal is judged manually. The braking force, the opening time, and the closing time of the brake are often empirical parameters input during the first debugging, and it is very inconvenient to adjust during the process, resulting in poor braking safety of the mine hoist. Moreover, the underground loading system is manually loaded, and it is not easy to ensure the loading accuracy, resulting in low safety of the system operation. The main power drive system, the loading system, and the unloading system operate independently of each other, and are independently operated by different operators, with poor coordination and low operating stability of the entire system. The main power drive system consists of a high-voltage frequency converter, a high-voltage three-phase asynchronous motor, a high-speed coupling, a speed reducer, a low-speed coupling, and a hoisting drum. The main power drive system has the disadvantages of low efficiency, high noise, low energy efficiency, large vibration, low safety and reliability, high energy consumption, low position control accuracy, and difficult starting. The traditional power drive system and its control method of the mine hoist have problems such as high labor intensity, low automation level, poor working environment, low safety, low operating stability, and high energy consumption.

[0004] The Chinese patent with the application number 202411578253.7, titled "Monitoring Method, Monitoring Device and Mine Hoist Monitoring System for Mine Hoist", monitors the operating condition data of the motor, including at least motor data, brake shoe clearance, operating environment data and temperature rise data, and takes corresponding countermeasures for the mine hoist according to each analysis result. However, it lacks the data monitoring of the entire mine hoisting system, including the monitoring of the capacity during coal loading and unloading, and does not have a variable frequency speed regulation system, so it cannot accurately control the working state of the system and wastes energy.

[0005] The information disclosed in this background art section is only intended to enhance the overall understanding of the present invention and should not be regarded as an admission or any form of implication that this information constitutes the prior art already known to those of ordinary skill in the art. Summary of the Invention

[0006] The purpose of the present invention is to overcome the deficiencies in the prior art and provide a servo permanent magnet direct drive system and control method for an unattended mine hoist. By connecting the main drive system, loading system, unloading system, and braking safety monitoring system of the mine hoist through a main hoisting control system into an independent and interrelated organic whole, the operation, monitoring, and safety protection of this system are automatically completed by the main hoisting control system, achieving one-key start and unattended operation. Moreover, with a servo permanent magnet direct drive motor as the power source, the system is more energy-efficient and convenient to control the speed to reduce impact fluctuations.

[0007] To solve the above technical problems, the present invention is implemented by adopting the following technical solutions: An unattended servo permanent magnet direct drive system for mine hoists, comprising a servo permanent magnet direct drive motor system, a loading system, an unloading system, a braking safety monitoring system and a hoisting main control system; the servo permanent magnet direct drive motor system is used to provide power for the hoist and also to drive the loading system and the unloading system respectively for loading and unloading materials; the servo permanent magnet direct drive motor system, the loading system and the unloading system are all connected to the hoisting main control system and operate under the control of the hoisting main control system; when the signals between the servo permanent magnet direct drive motor system, the loading system and the unloading system and the main control system are interrupted, the servo permanent magnet direct drive motor system and the loading system automatically perform loading, and the servo permanent magnet direct drive motor system and the unloading system automatically perform unloading; the braking safety monitoring system is used to provide status monitoring and warning information for the servo permanent magnet direct drive motor system; the hoisting main control system includes three switchable modes: maintenance mode, manual mode and unattended mode: when the maintenance mode is running, the mine hoist can only run at a low speed of 5% of the maximum running speed; when the manual mode is running, the operator of the mine hoist controls the running speed of the mine hoist through a handle, and the maximum running speed can be set up to 80% of the limit running speed at most; when the unattended mode is running, the hoist operator can set the weight of the materials lifted by the mine hoist each time, the target total weight of the lift or the total number of lifts, the maximum lifting speed, and the maximum allowable current of the servo permanent magnet direct drive motor system, and the maximum running speed of the mine hoist can be set up to the limit running speed at most; the hoisting main control system is respectively connected to the servo permanent magnet direct drive motor system, the loading system, the unloading system and the braking safety monitoring system through signal lines and can control the running parameters and running states of the servo permanent magnet direct drive motor system, the loading system and the unloading system; when the braking safety monitoring system detects any abnormal working information of the servo permanent magnet direct drive motor system, the loading system and the unloading system, it sends the abnormal working information to the hoisting main control system, and the hoisting main control system selects a disposal method according to the fault level corresponding to the abnormal working information. When it is judged as a serious fault, the unattended servo permanent magnet direct drive system for mine hoists will switch out of the unattended mode, the braking safety monitoring system issues a fault signal, and the unattended servo permanent magnet direct drive system for mine hoists and the hoist are only allowed to run in the maintenance mode state.

[0008] The servo permanent magnet direct drive motor system, the loading system and the unloading system are connected into an organic whole through the hoisting main control system. The whole system realizes one-key start and unattended operation, reduces the labor intensity of workers, and improves the working efficiency of the system. The servo permanent magnet direct drive motor is used to replace the traditional high-voltage three-phase asynchronous motor, high-speed coupling and reducer. The servo permanent magnet direct drive motor has a simple structure, high efficiency, high power factor, high overload multiple, high safety and reliability, realizes low-speed high torque, high efficiency and energy saving. The hoisting main control system includes three switchable modes: maintenance mode, manual mode and unattended mode, which ensures the safety of the whole system operation.

[0009] Optionally, the servo permanent magnet direct drive motor system includes an AC power supply, a variable frequency drive system, a servo permanent magnet direct drive motor, a hydraulic expansion coupling, a hoisting drum, a braking device, and a hoist position detection encoder. The AC power supply is connected to the servo permanent magnet direct drive motor through the variable frequency drive system. The servo permanent magnet direct drive motor and the hoisting drum are connected through a hydraulic expansion coupling. A braking device is provided at the non-drive end of the servo permanent magnet direct drive motor. A hoist position detection encoder is installed on the main shaft of the servo permanent magnet direct drive motor. By using the sensorless vector control technology (SVC) for frequency conversion starting through the variable frequency drive system and the servo permanent magnet direct drive motor, slow and uniform starting of the system transmission can be achieved, with a large starting torque, fast dynamic response, and strong overload capacity, avoiding the impact on the power grid caused by the large current at the moment of starting.

[0010] Optionally, the variable frequency drive system includes two independent power supplies, two identical frequency converters, and a high-voltage automatic switching cabinet. Voltage detection devices and harmonic detection devices are installed on both independent power supplies. The measured voltage values, voltage fluctuation ranges, and harmonic component information are all sent to the main hoisting control system. Each frequency converter is connected in parallel to the power supply circuit. The input side of each frequency converter is connected to an independent power supply respectively, and the output side of each frequency converter is connected to a high-voltage automatic switching cabinet at the same time. The high-voltage switching cabinet can be controlled by the main hoisting control system to select one of the power supplies and the corresponding frequency converter to connect. The output side of the automatic switching cabinet is connected to the servo permanent magnet direct drive motor. The servo permanent magnet direct drive motor is powered by the two frequency converters alternately. The main hoisting control system automatically selects one of the two power supplies according to the power supply quality of the power supply, and the other is in standby. The frequency converter is a four-quadrant frequency converter. When the hoisting drum drives the loaded material to lower, the power of the servo permanent magnet direct drive motor itself provides braking force and reverse hoisting force for the servo permanent magnet direct drive motor system. At the same time, the variable frequency drive system can supply power to the power grid in reverse, realizing resource conservation. The fact that the servo permanent magnet direct drive motor is powered by the two frequency converters alternately makes the frequency conversion movement of the servo permanent magnet direct drive motor more stable.

[0011] Optionally, a hoist position detection encoder is provided on the main shaft of the servo permanent magnet direct drive motor. The signal of the hoist position detection encoder is provided to the main hoisting control system for comprehensively judging the position of the mine hoist and the electromagnetic phase of the servo permanent magnet direct drive motor itself, realizing the active predictive operation control of the mine hoist, predicting the operation state of the mine hoist according to the detection data, and playing an important role in the precise control of the whole system.

[0012] Optionally, the servo permanent magnet direct drive motor system further includes a permanent magnet motor cooling device. The permanent magnet motor cooling device is connected to the main hoist control system through a signal line. Information about the start / stop and working status of the permanent magnet motor cooling device is sent into the main hoist control system through the signal line, and the permanent magnet motor cooling device reduces the situation where the servo permanent magnet direct drive motor malfunctions due to overheating.

[0013] Optionally, the braking device includes a proportional output hydraulic station, a brake disc, and a brake. The brake disc is installed on the side of the hoisting drum, and the brake is installed on both sides of the brake disc. The brake is connected to the proportional output hydraulic station through a hydraulic pipe to prevent the hoisting drum from rotating automatically after the servo permanent magnet direct drive motor is damaged, resulting in system operation errors.

[0014] Optionally, the loading system includes an underground storage bin, an underground storage bin level detection device, a feeder, a feeding belt conveyor, a feeding belt conveyor frequency converter, a weighing hopper, an electronic scale, an intelligent camera, and a loading control system. The coal inside the underground storage bin is transported to the weighing hopper through the feeder and the feeding belt conveyor. An electronic scale is arranged on the lower surface inside the weighing hopper, and the weighing hopper is connected to the servo permanent magnet direct drive motor system. The loading system receives the level detected by the underground storage bin level detection device, the weight of the electronic scale, and the working status of the feeder, the feeding belt conveyor, the feeding belt conveyor frequency converter, and the feeding hopper, as well as the control information sent by the main control system, and controls the working parameters and working status of the feeder, the feeding belt conveyor, the feeding belt conveyor frequency converter, and the feeding hopper. The underground storage bin level detection device is installed on the top of the underground storage bin and can detect the level of the underground storage bin. When the level is below the warning line, the loading system will automatically stop working, and at the same time, send the coal shortage information to the main hoist control system through the loading control system. The main control system will send a corresponding prompt message to the mine hoist operator. The feeder is controlled by frequency conversion and automatically selects the loading speed according to the set material weight and the total target amount of materials transported in a shift, and loads the materials into the mine hoist. After each loading is completed, the loading control system will timely transmit the weight of the loaded materials in this loading to the main hoist control system. When the communication between the loading control system and the main hoist control system is abnormal or the loading control system cannot receive the control information sent by the main hoist control system for more than 1 loading cycle, the loading control system will work independently according to the control information and parameters given by the main control system last time until it receives that the level of the underground storage bin is below the warning line and automatically stops working, which is convenient for detecting the working status of the loading system and ensures that the loading system can also work independently when it cannot receive the signal from the main hoist control system, improving the stability of the system operation.

[0015] Optionally, the unloading system includes a mine hoist up-to-position travel switch, an above-ground storage bin, an above-ground storage bin level detection device, and an unloading control system. The unloading control system automatically records the weight of the material lifted each time, the cumulative number of lifts, the cumulative lifting weight, and the information indicating that the set shift time has arrived. The unloading control system sends corresponding prompt messages to the mobile phone of the mine hoist operator through the main hoisting control system. It controls the servo permanent magnet direct drive motor system of the weighing hopper to rise to an appropriate position through the mine hoist up-to-position travel switch, and conveys the material in the weighing hopper to the above-ground storage bin. The above-ground storage bin level detection device detects the internal level of the above-ground storage bin. When the communication between the unloading control system and the main hoisting control system is abnormal or no control information sent by the main hoisting control system can be received for more than one unloading cycle, the unloading control system will automatically work independently according to the control information and parameters given by the main control system last time until the lifting weight reaches the standard, the unloading bin is full, or the set shift time arrives and then automatically stops working. The unloading control system records the information of the unloading system, transmits it to the main hoisting control system, and then the main hoisting control system controls the unloading system to discharge materials, realizing one-key start and unattended operation of the system and improving the working efficiency of the system.

[0016] Optionally, the braking safety monitoring system analyzes the reliability of the braking device by monitoring the braking time of each braking of the braking device, the change trend of the braking force with the braking time, the gap between the brake disc and the brake, the actual brake opening time, the actual brake release time, the reverse distance, the braking hydraulic pressure, and the braking hydraulic flow information. If it is found that the above parameters exceed the safety range or there are potential safety hazards through calculation, it will limit the main hoisting control system through the main hoisting control system. The main hoisting control system cannot enter the unattended mode, and the mine hoist can only operate manually at low speed or in the maintenance mode through manual intervention. At the same time, the braking safety monitoring system will send corresponding prompt messages to the mobile phones of the mine hoist operator, equipment management, and equipment maintenance personnel through the main hoisting control system. The fault information can be detected in time and sent to relevant personnel via SMS, so that system faults can be detected in time, and the system safety and reliability are greatly improved.

[0017] Optionally, based on the set maximum operating speed of the mine hoist, the main hoisting control system predicts the operating current of the servo direct drive motor of the hoist under different speed and acceleration conditions based on the optimal energy-saving mode with the highest energy efficiency. The main hoisting control system calculates the low-speed creeping speed, acceleration time, constant speed, deceleration time in the termination section, low-speed creeping speed at the termination end, and operating speeds of each hoisting section of the mine hoist based on the predicted operating current of the servo direct drive motor, combined with the maximum operating current of the servo direct drive motor set by the hoist operator, the maximum operating speed of the hoist, and the results jointly calculated from the actual historical opening times, actual closing times, and reverse distance provided by the braking safety system, and controls the operating parameters given to the frequency converter according to this result; The main hoisting control system revises the frequency parameters of the frequency converter at any time according to the actual position information of the hoist, the weight of the loaded materials, the speed and acceleration of the hoist, so as to control the information of the low-speed creeping speed, acceleration time, constant speed, deceleration time in the termination section, and low-speed creeping speed at the termination end of the hoist; The main hoisting control system calculates the reasonable opening time and closing time according to the weight of the materials loaded by the hoist, the low-speed creeping speed in the starting section, the low-speed creeping speed at the termination end, and the different weights of the materials loaded by the hoist, the low-speed creeping speed in the starting section, the low-speed creeping speed at the termination end, and the reverse distance recorded in history, adopting the strategy of giving priority to ensuring position accuracy, so as to ensure that the reverse distance is close to 0; The main hoisting control system predicts the minimum current of the servo permanent magnet direct drive motor for the hoist to rise according to the weight of the materials loaded by the hoist, the low-speed creeping speed in the starting section, and the historical current operating parameters. Combining with the parameters of the hoist position detection encoder on the main shaft of the servo permanent magnet direct drive motor, the brake is released during the period when the actual current of the servo permanent magnet direct drive motor is 110% - 130% of the minimum current of the servo permanent magnet direct drive motor for the hoist to rise, so that the servo permanent magnet direct drive motor will not start hard without releasing the brake, preventing the motor from being damaged due to overcurrent; The main hoisting control system is equipped with a mobile phone card that can send short messages, and can send the information of coal shortage in the underground storage bin, shift change time arrival, hoisting weight reaching the standard, full unloading bin, and heavy fault information sent by the servo permanent magnet direct drive motor system, loading system, and unloading system, as well as the braking system safety hazards and shutdown or fault information caused by other abnormalities sent by the braking safety monitoring system, to the set mobile phone number; According to the information received by the main hoisting control system, the most accurate control method is obtained through summary calculation, ensuring the safe operation of the system to the greatest extent. All fault information can be detected in time and sent to relevant personnel via mobile phone text messages, and system faults can be detected in time, greatly improving the safety and reliability of the system.

[0018] Compared with the prior art, the beneficial effects achieved by the present invention are: 1. The main control system is upgraded to connect the servo permanent magnet direct drive motor system, loading system and unloading system into an organic whole. The whole system realizes one-key start and unattended operation, reduces the labor intensity of workers and improves the working efficiency of the system.

[0019] 2. The servo permanent magnet direct drive motor is used to replace the traditional high-voltage three-phase asynchronous motor, high-speed coupling and speed reducer. The servo permanent magnet direct drive motor has a simple structure, high efficiency, high power factor, high overload multiple, high safety and reliability, realizes low-speed and high-torque, and is energy-efficient.

[0020] 3. The servo permanent magnet direct drive motor has low noise and small vibration. There is no need for operation during underground loading. The underground material level detection and the material level detection of the above-ground storage bin are automatically realized through the remote material level detection device, and the working environment is more friendly.

[0021] 4. All fault information can be detected in time and sent to relevant personnel via SMS. System faults can be detected in time, and the system safety and reliability are greatly improved.

[0022] 5. The system uses sensorless vector control technology (SVC) for frequency conversion starting, which can realize slow and uniform starting of the system drive, with large starting torque, fast dynamic response and strong overload capacity, avoiding the impact on the power grid caused by the large current at the moment of starting and the mechanical impact on the drive system caused by torque fluctuation, thus reducing the power grid faults and mechanical faults of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The figure shows a schematic diagram of the working process of the total system of the servo permanent magnet direct drive system for an unattended mine hoist according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] The technical solution of the present invention will be described in detail below with reference to the drawings and specific embodiments. It should be understood that the specific features in the embodiments of the present invention and the embodiments are detailed descriptions of the technical solution of the present invention, rather than limitations on the technical solution of the present invention. Without conflict, the technical features in the embodiments of the present invention and the embodiments can be combined with each other. Embodiment

[0025] An unattended servo permanent magnet direct drive system for mine hoists, comprising a servo permanent magnet direct drive motor system, a loading system, an unloading system, a braking safety monitoring system, and a hoisting main control system. The servo permanent magnet direct drive motor system is used to provide power for the hoist and also drive the loading system and the unloading system respectively for loading and unloading materials. The servo permanent magnet direct drive motor system, the loading system, and the unloading system are all connected to the hoisting main control system and operate under the control of the hoisting main control system. When the signals between the servo permanent magnet direct drive motor system, the loading system, and the unloading system and the main control system are interrupted, the servo permanent magnet direct drive motor system and the loading system automatically perform loading, and the servo permanent magnet direct drive motor system and the unloading system automatically perform unloading. The braking safety monitoring system is used to provide status monitoring and warning information for the servo permanent magnet direct drive motor system, and provide relevant records of the fault type and occurrence time for the hoist system management personnel, enabling the hoist management personnel to master the operating status of the hoist, so that the hoist management personnel can further optimize the control process, compress each hoisting link, reduce the energy consumption during hoisting, and improve the quality of the hoisting process.

[0026] The hoisting main control system is respectively connected to the servo permanent magnet direct drive motor system, the loading system, the unloading system, and the braking safety monitoring system through signal lines, and can control the operating parameters and operating status of the servo permanent magnet direct drive motor system, the loading system, and the unloading system. When the braking safety monitoring system detects any abnormal working information in the servo permanent magnet direct drive motor system, the loading system, and the unloading system, it sends the abnormal working information to the hoisting main control system. The hoisting main control system selects a disposal method according to the fault level corresponding to the abnormal working information. When it is judged as a serious fault, the unattended servo permanent magnet direct drive system for mine hoists will switch out of the unattended mode, the braking safety monitoring system issues a fault signal, and it is set that the unattended servo permanent magnet direct drive system for mine hoists and the hoist are only allowed to operate in the maintenance mode state.

[0027] The hoisting main control system is respectively connected to the servo permanent magnet direct drive motor system, the loading system, the unloading system, and the braking safety monitoring system through signal lines, and can control the operating parameters and operating status of the servo permanent magnet direct drive motor system, the loading system, and the unloading system. When the braking safety monitoring system detects any abnormal working information in the servo permanent magnet direct drive motor system, the loading system, and the unloading system, it sends the abnormal working information to the hoisting main control system. The hoisting main control system selects a disposal method according to the fault level corresponding to the abnormal working information. When it is judged as a serious fault, the unattended servo permanent magnet direct drive system for mine hoists will switch out of the unattended mode, the braking safety monitoring system issues a fault signal, and it is set that the unattended servo permanent magnet direct drive system for mine hoists and the hoist are only allowed to operate in the maintenance mode state.

[0028] The main control system is used to control the servo permanent magnet direct drive motor system to drive the loading system to pick up and load coal. Then, it controls the servo permanent magnet direct drive motor system to drive the loading system to move to the unloading system, and stores the coal in the loading system into the unloading system. The main control system for hoisting receives the abnormal working information sent by the servo permanent magnet direct drive motor system, the loading system, and the unloading system monitored by the braking safety monitoring system. The servo permanent magnet direct drive motor system, the loading system, and the unloading system are connected into an organic whole through the main control system for hoisting. The entire system realizes one-key start and unattended operation, reduces the labor intensity of workers, and improves the working efficiency of the system. The servo permanent magnet direct drive motor system includes an AC power supply, a variable frequency drive system, a servo permanent magnet direct drive motor, a hydraulic expansion coupling, a hoisting drum, a braking device, and a hoist position detection encoder. The AC power supply is connected to the servo permanent magnet direct drive motor through the variable frequency drive system. The servo permanent magnet direct drive motor and the hoisting drum are connected through the hydraulic expansion coupling. The tightening force of the hydraulic expansion coupling can be adjusted through the internal hydraulic pressure. When the hydraulic pressure is 0, the connection force between the hydraulic expansion coupling and the servo permanent magnet direct drive motor and the hoisting drum is 0, and it can be easily disassembled.

[0029] A braking device is provided at the non-driving end of the servo permanent magnet direct drive motor. A hoist position detection encoder is installed on the main shaft of the servo permanent magnet direct drive motor. The servo permanent magnet direct drive motor system starts frequency conversion by using sensorless vector control technology through the control system, and realizes the frequency conversion speed regulation of the entire hoisting system through the frequency converter and the brake, so that the hoisting system can achieve speed regulation during the hoisting and lowering processes, and gives play to the characteristics of the speed regulation type servo permanent magnet direct drive motor in each starting link, speed-up link, constant speed link, and deceleration link. When the movement is about to end, it decelerates slowly to avoid excessive speed and impact force at the end of the movement, which may affect the service life, shorten the operation cycle, improve the production capacity, and at the same time ensure the stability and safety of the loading system operation.

[0030] The variable-frequency drive system includes two independent power supplies, two sets of identical frequency converters, and a high-voltage automatic switching cabinet. Voltage detection devices and harmonic detection devices are installed on both independent power supplies. The measured voltage values, voltage fluctuation ranges, and harmonic component information are all sent to the hoisting main control system. Each frequency converter is connected in parallel to the power supply circuit. The input side of each frequency converter is respectively connected to an independent power supply, and the output side of each frequency converter is simultaneously connected to a high-voltage automatic switching cabinet. The high-voltage switching cabinet can be controlled by the hoisting main control system to select one of the power supplies and the corresponding frequency converter to connect. The output side of the automatic switching cabinet is connected to the servo permanent magnet direct drive motor. The servo permanent magnet direct drive motor is alternately powered by two frequency converters. The hoisting main control system automatically selects one of the two power supplies according to the power supply quality of the power supply, and the other is in standby. The hoisting main control system simultaneously receives the power supply quality information of the voltage, voltage fluctuation amplitude, and harmonic content of the two power supplies, and comprehensively considers the above information to automatically select the power supply with a small difference between the power supply voltage and the rated voltage, a small voltage fluctuation amplitude, and a low harmonic content for power supply. When the above power supply quality information cannot meet the requirements at the same time, a fuzzy algorithm is used to select the relatively optimal circuit for power supply through the high-voltage automatic switching cabinet.

[0031] The fuzzy algorithm gives priority to a small voltage fluctuation amplitude; if the voltage fluctuation amplitudes are similar, select the power supply circuit with a small harmonic component; if both amplitudes are large, randomly select one power supply to work for one coal hoisting shift, and then replace it in the next shift. Then select the power supply circuit with a small corresponding supply current of the working parameters.

[0032] The frequency converter is a four-quadrant frequency converter. When the hoisting drum drives the loaded material to lower, the power of the servo permanent magnet direct drive motor itself provides braking force and reverse hoisting force for the servo permanent magnet direct drive motor system. At the same time, the variable-frequency drive system can supply power to the power grid in reverse. The reverse power supply to the power grid realizes resource conservation. The fact that the servo permanent magnet direct drive motor is alternately powered by two frequency converters makes the variable-frequency movement of the servo permanent magnet direct drive motor more stable.

[0033] A hoist position detection encoder is set on the main shaft of the servo permanent magnet direct drive motor. The signal of the hoist position detection encoder is provided to the hoisting main control system, which is used to comprehensively judge the position of the mine hoist and the electromagnetic phase of the servo permanent magnet direct drive motor itself, realize the active predictive operation control of the mine hoist, predict the operation state of the mine hoist according to the detection data, and play an important role in the precise control of the whole system.

[0034] The servo permanent magnet direct drive motor system also includes a permanent magnet motor cooling device. The permanent magnet motor cooling device is connected to the main control system of the hoist through a signal line. Information about the start / stop and working status of the permanent magnet motor cooling device is sent into the main control system of the hoist through the signal line. The permanent magnet motor cooling device includes a circulating water circuit, a cooling water pump, two sets of air-water heat exchangers, a circulating water flowmeter, a circulating water temperature gauge, and two sets of refrigerating fans. The two sets of air-water heat exchangers are connected in series on the circulating water circuit, and each set of air-water heat exchanger corresponds to a refrigerating fan for forced air refrigeration. The start / stop of the two sets of refrigerating fans is directly controlled by the main control system of the hoist to control the circulating water temperature between 20°C and 30°C. When the circulating water temperature is lower than 20°C, both sets of refrigerating fans stop working. When the circulating water temperature is higher than 28°C, both sets of refrigerating fans are turned on for forced refrigeration. The permanent magnet motor cooling device reduces the situation where the servo permanent magnet direct drive motor malfunctions due to overheating, and facilitates the control and monitoring of the permanent magnet motor cooling device.

[0035] The braking device includes a proportional output hydraulic station, a brake disc, and brakes. The brake disc is installed on the side of the hoist drum, and the brakes are installed on both sides of the brake disc. The brakes are connected to the proportional output hydraulic station through hydraulic pipes to prevent the hoist drum from rotating automatically after the servo permanent magnet direct drive motor is damaged, resulting in system operation errors.

[0036] The loading system includes an underground storage bin, an underground storage bin level detection device, a feeder, a feeding belt conveyor, a feeding belt conveyor frequency converter, a weighing hopper, an electronic scale, an intelligent camera, and a loading control system. The coal inside the underground storage bin is transported to the weighing hopper through the feeder and the feeding belt conveyor. An electronic scale is arranged on the lower surface inside the weighing hopper. The weighing hopper is connected to the servo permanent magnet direct drive motor system. The loading system receives the level detected by the underground storage bin level detection device, the weight of the electronic scale, and the control information sent by the main control system regarding the working status of the feeder, the feeding belt conveyor, the feeding belt conveyor frequency converter, and the feeding hopper, and controls the working parameters and working status of the feeder, the feeding belt conveyor, the feeding belt conveyor frequency converter, and the feeding hopper. The underground storage bin level detection device is installed on the top of the underground storage bin and can detect the level of the underground storage bin. When the level is below the warning line, the loading system will automatically stop working, and at the same time, send the coal shortage information to the main control system of the hoist through the loading control system. The main control system will send a corresponding prompt message to the operator of the mine hoist to avoid air transportation of the loading system and save energy.

[0037] The feeder is controlled by frequency conversion. According to the set material weight and the total target amount of conveyed materials in a shift, it automatically selects the loading speed and accurately loads the materials into the mine hoist. After each loading is completed, the loading control system will promptly transmit the weight of the loaded materials in this loading to the main control system of the hoist. When there is an abnormality in the communication between the loading control system and the main control system of the hoist or no control information sent by the main control system of the hoist can be received for more than 1 loading cycle, the loading control system will work independently according to the control information and parameters given by the main control system last time until it receives that the material level in the underground storage bin is lower than the warning line and then automatically stops working. This is convenient for detecting the working state of the loading system and ensures that the loading system can also work alone when the signal from the main control system of the hoist cannot be received, improving the stability of the system operation.

[0038] The unloading system includes the up-to-position travel switch of the mine hoist, the above-ground storage bin, the material level detection device of the above-ground storage bin, and the unloading control system. The unloading control system automatically records the weight of the materials lifted each time, the cumulative number of lifts, the cumulative lifting weight, and the information when the set shift change time arrives. The unloading control system sends corresponding prompt messages to the mobile phone of the mine hoist operator through the main control system of the hoist, and the on-site alarm also gives prompt information at the same time. The servo permanent magnet direct drive motor system is controlled by the up-to-position travel switch of the mine hoist to control the quantitative hopper to rise to a suitable position, and the materials in the quantitative hopper are conveyed to the above-ground storage bin. The material level detection device of the above-ground storage bin detects the internal material level of the above-ground storage bin. When there is an abnormality in the communication between the unloading control system and the main control system of the hoist or no control information sent by the main control system of the hoist can be received for more than 1 unloading cycle, the unloading control system will work independently according to the control information and parameters given by the main control system last time until the lifting weight reaches the standard, the unloading bin is full, or the set shift change time arrives and then automatically stops working. The unloading control system records the information of the unloading system and transmits it to the main control system of the hoist, and then the main control system of the hoist controls the unloading system to discharge materials, realizing one-key startup and unattended operation of the system and improving the working efficiency of the system.

[0039] The braking safety monitoring system analyzes the reliability of the braking device by monitoring the time of each braking, the change trend of braking force with braking time, the clearance between the brake disc and the brake, the actual brake opening time, the actual brake release time, the reverse distance, the braking hydraulic pressure, and the braking hydraulic flow information. If it is found that the above parameters exceed the safety range or there are potential safety hazards through calculation, the main hoist control system will be restricted through the main hoist control system. The main hoist control system shall not enter the unattended mode, and the mine hoist can only operate manually at low speed or in the maintenance mode through manual intervention. At the same time, the braking safety monitoring system will send corresponding prompt messages to the mobile phones of the mine hoist operator, equipment management, and equipment maintenance personnel through the main hoist control system. The fault information can be detected in time and sent to relevant personnel through text messages, and the system fault can be detected in time, greatly improving the system safety and reliability.

[0040] Based on the highest operating speed of the mine hoist set, the main hoist control system predicts the operating current of the servo direct drive motor under different speed and acceleration conditions based on the optimal energy-saving mode with the highest energy efficiency. According to the predicted operating current of the servo direct drive motor, the main hoist control system combines the maximum operating current of the servo direct drive motor set by the hoist operator, the highest operating speed of the hoist, and the results calculated jointly from the actual historical brake opening times, actual brake release times, and reverse distances provided by the braking safety system to calculate the low-speed creep speed, acceleration time, constant speed, deceleration time at the end, low-speed creep speed at the end of the hoist during the starting section, and the operating speeds of each lifting section, and controls the operating parameters given to the frequency converter according to this result; The main hoist control system revises the frequency parameters of the frequency converter at any time according to the actual position information of the hoist, the weight of the transported materials, the speed and acceleration of the hoist, so as to more accurately control the information of the low-speed creep speed, acceleration time, constant speed, deceleration time at the end, and low-speed creep speed at the end of the starting section of the hoist. The main hoist control system adopts the strategy of giving priority to ensuring position accuracy according to the weight of the transported materials by the hoist, the low-speed creep speed at the starting section, the low-speed creep speed at the end, and the weights of different transported materials, low-speed creep speeds at the starting section, low-speed creep speeds at the end, and reverse distances recorded in history to calculate reasonable brake opening times and brake release times to ensure that the reverse distance is close to 0; The main hoist control system predicts the minimum current of the servo permanent magnet direct drive motor that the hoist can lift according to the weight of the transported materials by the hoist, the low-speed creep speed at the starting section, and the historical current operating parameters. Combining the parameters of the hoist position detection encoder on the main shaft of the servo permanent magnet direct drive motor, the brake is opened during the period when the actual current of the servo permanent magnet direct drive motor is 110% - 130% of the minimum current of the servo permanent magnet direct drive motor that the hoist can lift, so that the servo permanent magnet direct drive motor will not drive hard without opening the brake, preventing the motor from being damaged due to overcurrent; The main hoisting control system is equipped with a mobile phone card that can send short messages, and can send the information about the shortage of coal in the underground storage bunker, the arrival of the shift time, the compliance of the hoisting weight, the working node information of the full unloading bunker, and the heavy fault information sent by the servo permanent magnet direct drive motor system, the loading system and the unloading system, as well as the shutdown or fault information caused by the safety hazards of the braking system and other abnormalities sent by the braking safety monitoring system, to the set mobile phone number. According to the information received by the main hoisting control system, the most accurate control method is obtained through summary calculation to ensure the safe operation of the system to the greatest extent. All fault information can be detected in time and sent to relevant personnel via mobile phone text messages, so that system faults can be detected in time, and the safety and reliability of the system are greatly improved.

[0041] The term "and / or" is merely a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0042] The embodiments of the present invention have been described above in conjunction with the accompanying drawings. However, the present invention is not limited to the above specific embodiments. The above specific embodiments are merely illustrative and not restrictive. Under the inspiration of the present invention, those of ordinary skill in the art can also make many forms without departing from the purpose of the present invention and the scope protected by the claims. All of these are within the protection scope of the present invention.

Claims

1. A servo permanent magnet electric direct drive system for an unattended mine hoist, characterized in that: It includes servo permanent magnet direct drive motor system, loading system, unloading system, brake safety monitoring system and lifting main control system; The servo permanent magnet direct drive motor system is used to provide power for the elevator, and is also used to drive the loading system and unloading system to load and unload materials respectively; The servo permanent magnet direct drive motor system, loading system and unloading system are all connected to the lifting main control system and are controlled and operated by the lifting main control system; when the signal between the servo permanent magnet direct drive motor system, loading system and unloading system and the main control system is interrupted, the servo permanent magnet direct drive motor system and loading system automatically load, and the servo permanent magnet direct drive motor system and unloading system automatically unload; The brake safety monitoring system is used to provide status monitoring and early warning information for the servo permanent magnet direct drive motor system; The main lifting control system includes three switchable modes: maintenance, manual and unattended: When operating in maintenance mode, the mine hoist can only run at a low speed of 5% of the maximum operating speed; When operating in manual mode, the mine hoist operator controls the operating speed of the mine hoist through the handle, and the maximum operating speed can be set to 80% of the maximum operating speed; When the unattended mode is in operation, the hoist operator can set the weight of the material lifted by the mine hoist at a time, the target total lifting weight or total number of lifts, the maximum lifting speed, and the maximum allowable current of the servo permanent magnet direct drive motor system. The maximum operating speed of the mine hoist can be set to the maximum operating speed; The lifting main control system is connected to the servo permanent magnet direct drive motor system, loading system, unloading system and brake safety monitoring system through signal lines, and can control the operating parameters and operating status of the servo permanent magnet direct drive motor system, loading system and unloading system; When the braking safety monitoring system detects any abnormal working information in the servo permanent magnet direct drive motor system, loading system and unloading system, the abnormal working information will be sent to the hoisting main control system. The hoisting main control system selects the handling method according to the fault level corresponding to the abnormal working information. When it is judged to be a serious fault, the servo permanent magnet electric direct drive system for the unmanned mine hoist will switch out of the unmanned mode, and the braking safety monitoring system will send a fault signal. The servo permanent magnet electric direct drive system for the unmanned mine hoist and the hoist are set to only be allowed to operate in maintenance mode.

2. The servo permanent magnet electric direct drive system for unattended mine hoist according to claim 1 is characterized in that: The servo permanent magnet direct drive motor system includes an AC power supply, a variable frequency drive system, a servo permanent magnet direct drive motor, a hydraulic expansion coupling, a lifting drum, a braking device and a lifting machine position detection encoder. The AC power supply is connected to the servo permanent magnet direct drive motor through the variable frequency drive system, the servo permanent magnet direct drive motor and the lifting drum are connected through a hydraulic expansion coupling, the non-driving end of the servo permanent magnet direct drive motor is provided with a braking device, and the main shaft of the servo permanent magnet direct drive motor is installed with a lifting machine position detection encoder.

3. The servo permanent magnet electric direct drive system for unattended mine hoist according to claim 2 is characterized in that: The variable frequency drive system includes two independent power supplies, two sets of identical frequency converters and a high-voltage automatic switching cabinet. The two independent power supplies are equipped with voltage detection devices and harmonic detection devices. The measured voltage value, voltage fluctuation range and harmonic component information are sent to the lifting main control system. Each frequency converter is connected in parallel in the power supply circuit. The input side of each frequency converter is connected to an independent power supply, and the output side of each frequency converter is connected to a high-voltage automatic switching cabinet at the same time. The high-voltage switching cabinet can be controlled by the lifting main control system to select one of the power supplies and the corresponding frequency converter. The output side of the automatic switching cabinet is connected to the servo permanent magnet direct drive motor, which is alternately powered by two frequency converters. The lifting main control system automatically selects one of the two routes for power supply according to the power supply quality of the power supply, and the other route is standby. The frequency converter is a four-quadrant frequency converter. When the lifting drum drives the loaded material to be lowered, the power of the servo permanent magnet direct drive motor itself provides braking force and reverse lifting force for the servo permanent magnet direct drive motor system, and the variable frequency drive system can reversely supply power to the power grid.

4. The servo permanent magnet electric direct drive system for unattended mine hoist according to claim 3 is characterized in that: The servo permanent magnet direct drive motor is provided with a hoist position detection encoder on its main shaft. The signal of the hoist position detection encoder is provided to the hoist main control system for comprehensive judgment of the position of the mine hoist and the electromagnetic phase of the servo permanent magnet direct drive motor itself, so as to realize active predictive operation control of the mine hoist.

5. The servo permanent magnet electric direct drive system for unattended mine hoist according to claim 4 is characterized in that: The servo permanent magnet direct drive motor system also includes a permanent magnet motor cooling device, which is connected to the hoist main control system through a signal line. The start and stop and working status information of the permanent magnet motor cooling device are sent to the hoist main control system through the signal line.

6. The servo permanent magnet electric direct drive system for unattended mine hoist according to claim 5 is characterized in that: The braking device comprises a proportional output hydraulic station, a brake disc and a brake. The brake disc is installed on the side of the lifting drum, and the brake is installed on both sides of the brake disc. The brake is connected to the proportional output hydraulic station through a hydraulic pipe.

7. The servo permanent magnet electric direct drive system for unattended mine hoist according to claim 6 is characterized in that: The loading system includes an underground storage bin, a material level detection device for the underground storage bin, a feeder, a feeding belt conveyor, a feeding belt conveyor frequency converter, a quantitative bucket, an electronic scale, an intelligent camera and a loading control system; The coal inside the underground storage bin is transported to the quantitative bucket through the feeder and the feeding belt conveyor. The lower surface of the quantitative bucket is provided with an electronic scale, and the quantitative bucket is connected to the servo permanent magnet direct drive motor system; The loading system receives the material level detected by the material level detection device of the underground storage bin, the weight of the electronic scale, the working status of the feeder, the feeding belt conveyor, the feeding belt conveyor frequency converter, the feeding hopper, and the control information sent by the main control system, and controls the working parameters and working status of the feeder, the feeding belt conveyor, the feeding belt conveyor frequency converter, and the feeding hopper; The underground storage bin material level detection device is installed on the top of the underground storage bin, which can detect the material level of the underground storage bin. When the material level is below the warning line, the loading system will automatically stop working, and at the same time send the coal shortage information to the main control system of the hoist through the loading control system, and the main control system will send a corresponding prompt message to the mine hoist operator; The feeder is controlled by frequency conversion. It automatically selects the loading speed according to the set material weight and the total amount of material to be transported in a shift, and loads the material into the mine hoist. After each loading is completed, the loading control system will promptly transmit the weight of the loaded material to the main control system of the hoist. When there is an abnormality in the communication between the loading control system and the hoist main control system or the loading control system fails to receive the control information sent by the hoist main control system for more than one loading cycle, the loading control system will automatically and independently work according to the control information and parameters given by the last main control system until it receives the message that the material level in the underground storage bin is below the warning line and automatically stops working.

8. The servo permanent magnet electric direct drive system for unattended mine hoist according to claim 7 is characterized in that: The unloading system includes a mine hoist rising position travel switch, an above-ground storage bin, an above-ground storage bin material level detection device and an unloading control system; The unloading control system automatically records the weight of each lifted material, the cumulative number of lifts, the cumulative weight of lifts and the set shift handover time. The unloading control system sends corresponding prompt messages to the mine hoist operator's mobile phone through the lifting main control system; The mine hoist is raised to the right position through the stroke switch to control the quantitative bucket servo permanent magnet direct drive motor system to rise to the appropriate position, and the material in the quantitative bucket is transported to the storage bin on the well. The material level detection device of the storage bin on the well detects the internal material level of the storage bin on the well; When there is an abnormality in the communication between the unloading control system and the elevator main control system or the control information sent by the elevator main control system cannot be received for more than one unloading cycle, the unloading control system will automatically and independently work according to the control information and parameters given by the last main control system until the lifting weight reaches the standard, the unloading bin is full, or the set shift time is reached and it automatically stops working.

9. The servo permanent magnet electric direct drive system for unattended mine hoist according to claim 8, characterized in that: The brake safety monitoring system analyzes the reliability of the brake device by monitoring the time of each braking of the brake device, the trend of braking force changing with braking time, the gap between the brake disc and the brake, the actual gate opening time, the actual gate unloading time, the reversing distance, the brake hydraulic pressure and the brake hydraulic flow. If it is found that the above parameters exceed the safety range or there are safety hazards through calculation, the lifting main control system will be restricted through the lifting main control system. The lifting main control system shall not enter the unattended mode, and the mine hoist can only be operated manually at a low speed or in maintenance mode through manual intervention. At the same time, the brake safety monitoring system will send corresponding prompt messages to the mobile phones of the mine hoist operator, equipment management and equipment maintenance personnel through the lifting main control system.

10. The servo permanent magnet electric direct drive system for unattended mine hoist according to claim 9, characterized in that: The hoisting main control system predicts the operating current of the servo direct drive motor of the hoist under different speed and acceleration conditions based on the set maximum operating speed of the mine hoist and the optimal energy-saving mode with the highest energy efficiency; The hoisting main control system calculates the starting slow creeping speed, acceleration time, uniform speed, terminal deceleration time, terminal slow creeping speed, and operating speed of each hoisting section of the mine hoist based on the predicted running current of the servo direct drive motor, the maximum running current of the servo direct drive motor set by the hoist operator, the highest running speed of the hoist, and the actual historical gate opening time, actual gate unloading time, and reverse distance provided by the brake safety system, and controls the inverter operating parameters according to the results; The main control system of the elevator can revise the frequency parameters of the inverter at any time according to the actual position information of the elevator, the weight of the transported materials, the speed and acceleration of the elevator to control the information of the low-speed creeping speed, acceleration time, uniform speed, deceleration time of the terminal section, and low-speed creeping speed of the terminal end of the elevator; The main control system of the hoist adopts the strategy of giving priority to position accuracy to calculate the reasonable gate opening time and gate unloading time according to the weight of the hoisting material, the low-speed creeping speed of the starting section, the low-speed creeping speed of the terminal end and the historical records of different hoisting material weights, the low-speed creeping speed of the starting section, the low-speed creeping speed of the terminal end and the reversing distance, so as to ensure that the reversing distance is close to 0; The hoisting main control system predicts the minimum current of the servo permanent magnet direct drive motor for hoisting according to the weight of the hoisting material, the low-speed creeping speed in the starting section and the historical current operating parameters. Combined with the parameters of the hoist position detection encoder on the main shaft of the servo permanent magnet direct drive motor, the hoisting main control system opens the gate in the time period when the actual current of the servo permanent magnet direct drive motor is 110%~130% of the minimum current of the servo permanent magnet direct drive motor for hoisting, so that the servo permanent magnet direct drive motor will not be forced to start without opening the gate, thereby preventing the motor from being damaged due to overcurrent; The lifting main control system is equipped with a mobile phone card that can send short messages. It can send information such as coal shortage in the underground storage bin, work node information such as the arrival of the shift handover time, the lifting weight reaching the standard, and the unloading bin being full, as well as serious fault information sent by the servo permanent magnet direct drive motor system, loading system and unloading system, as well as shutdown or fault information caused by safety hazards of the braking system and other abnormalities sent by the braking safety monitoring system to the set mobile phone number.

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