Rapid motor shutdown method

Abstract

The invention discloses a rapid motor shutdown method, and relates to the technical field of motor control, and the method comprises the steps: controlling a shutdown mode to stop to a fixed rotating speed, closing three upper bridges of a three-phase bridge rectifier circuit, opening three lower bridges at the same time to realize active shutdown, and adopting an active short circuit (ASC) braking mode. According to the invention, the rotating speed of the motor can be rapidly reduced in an extremely short time to realize a rapid shutdown function, meanwhile, the problem of uncontrollable deceleration caused by natural shutdown can be avoided, and the problems of long shutdown time and uncontrollable deceleration in a traditional Free Wheeling shutdown mode are effectively solved by adopting an ASC braking mode and a series of accurate control steps; by establishing the mathematical relationship model between the motor rotation speed and the control signal, the duty ratio of the control signal can be accurately calculated and adjusted according to the actual operation state and working condition of the motor, and it is ensured that the motor can rapidly and stably enter the rotation speed range suitable for shutdown.

Description

Technical Field

[0001] The invention relates to the technical field of motor control, and in particular to a motor rapid shutdown method. Background Art

[0002] Free Wheeling is a control method used in motor applications. When the motor enters the free rotation state, the power supply of the motor is disconnected, so that the motor can continue to rotate by inertia until it stops. The basic principle of Free Wheeling is to disconnect the driving power of the motor so that the motor rotor is no longer affected by the electromagnetic torque, and only relies on its own kinetic energy and the friction of the external load to gradually slow down until it stops. This method is usually used in situations where gradual shutdown is required to avoid the impact and wear caused by sudden shutdown, but the shutdown is slow and is not suitable for some special situations;

[0003] There are many problems with existing motors, including long downtime, uncontrollable deceleration, mechanical wear, system stability and environmental impact. For long downtime, free rotation shutdown relies on inertia to gradually decelerate. For uncontrollable deceleration, since the deceleration process only depends on external factors such as friction and air resistance, the deceleration process is uncontrollable. For mechanical wear, free rotation shutdown reduces electromagnetic shock, but due to long-term inertial operation, mechanical parts will still be subject to friction and wear, which may lead to more frequent maintenance and shorter equipment life in high-frequency start-stop applications. For system stability, in high-speed applications, the free rotation shutdown method may cause system instability. Since the motor loses electromagnetic control after power failure, it may cause unstable vibration of rotating parts, affecting the normal operation and safe use of the system. For environmental impact, under high load or special environment, long-term free rotation shutdown will cause overheating and other adverse environmental impacts. For this reason, we propose a motor rapid shutdown method. Summary of the invention

[0004] The object of the present invention is to provide a method for quickly stopping a motor.

[0005] In order to solve the problems raised in the above background technology, the present invention provides the following technical solutions: a method for rapid motor shutdown, including controlling the shutdown mode to stop at a fixed speed, closing the three upper bridges of the three-phase bridge rectifier circuit, and opening the three lower bridges to realize active shutdown, using the ASC braking mode, and the specific operation steps of the method for rapid motor shutdown are as follows:

[0006] Step 1: When the motor adopts the position sensorless control mode and receives the shutdown command, the motor speed is accurately controlled to the preset shutdown speed range using the closed-loop speed regulation technology, and the motor speed is calculated and adjusted according to the coefficient determined by the motor characteristics and the actual working conditions;

[0007] Step 2: Pre-configure the ASC braking parameters and strategies before the motor starts, and dynamically adjust the braking intensity and timing in real time according to the motor's operating status and load characteristics;

[0008] Step 3: When the motor speed increases abnormally and the system detects a serious fault signal, the ASC brake is immediately switched to a multi-phase conduction mode, and the specific phase windings of the motor are specially connected and combined according to a specific technical solution to form an efficient electromagnetic damping structure to quickly consume the kinetic energy of the motor;

[0009] Step 4: Build a real-time monitoring and data analysis system. The system can continuously detect the key parameters of the motor and transmit the data to the central processor in real time for analysis and processing. According to the real-time data, a separate mathematical model and algorithm are established to predict the operating status of the motor.

[0010] Step 5. Establish a fault monitoring and diagnosis model, introduce a large amount of historical fault data into the model library, monitor and record various fault types in real time, and quickly locate and analyze the fault when it occurs. Based on rich experience data and advanced analysis algorithms, provide detailed fault reports and accurate repair suggestions, and start the corresponding repair program according to the suggestions to perform accurate repair operations.

[0011] As a further solution of the present invention: In step 1, a mathematical relationship model between the motor speed and the control signal is established, the motor speed is marked as ω, the duty cycle of the control signal is d, and the load torque of the motor is T L , the moment of inertia of the motor is J. According to the dynamic equation and electrical equation of the motor, the following formula is obtained:

[0012] T e =K t ·i

[0013] Where K t is the torque constant of the motor, i is the phase current of the motor;

[0014] The equation of motion for the motor is:

[0015]

[0016] In the above formula, B ω Represents the friction torque term of the motor.

[0017] As a further solution of the present invention: in combination with the above formula, according to the actual measured motor current and speed, the duty cycle of the control signal is adjusted to control the speed of the motor. When a shutdown command is received, the duty cycle change Δd that needs to be adjusted is calculated according to the current motor speed and the target shutdown speed range, and the duty cycle is adjusted according to the control algorithm to control the motor speed within the preset shutdown speed range.

[0018] As a further solution of the present invention: in the step 2, before the motor is started, the initial parameters of the ASC braking are determined according to the rated parameters of the motor and the actual application scenario, and the initial conduction time of the ASC braking is set to t a , the initial off time is t b , according to the motor's inductance L, resistance R and motor speed n, the following formula is obtained:

[0019] τ=L / R

[0020] Among them, τ is the time constant of the calculation motor;

[0021] According to the initial conduction time t a According to the empirical formula t a =k1·τ, where k1 is a coefficient determined according to motor characteristics and actual working conditions, and the coefficient range is between 0.5-2;

[0022] According to the initial off time t b And it is determined according to the motor speed and load characteristics. The specific formula is as follows:

[0023]

[0024] Among them, is a coefficient determined according to actual conditions, and the coefficient range is between 0.1 and 1.

[0025] As a further solution of the present invention: when the motor speed increases, the conduction time t is reduced a and increase the off time t b , when the motor load increases, increase the conduction time t a , in order to establish a neural network controller, which outputs the optimal ASC braking parameter adjustment according to the input motor operating state parameters and load characteristic parameters.

[0026] As a further solution of the present invention: in step three, when the motor speed increases abnormally and the system detects a serious fault signal, the multi-phase conduction mode switching mechanism is immediately triggered, and two phases are selected for special connection according to the fault type and the operating status of the motor.

[0027] As a further solution of the present invention: in step four, the key parameters of the motor include speed, current, temperature and vibration frequency, and the external environment includes air pressure and humidity. Based on historical data and real-time parameters, the performance change trend of the motor in the future period is predicted, potential failure risks are discovered in advance, and corresponding countermeasures are taken in time to adjust and optimize.

[0028] As a further solution of the present invention: in the step four, a comprehensive sensor network is established to detect the key parameters of the motor in real time, and the data collected by the sensor is transmitted to the central processing unit in real time through the data transmission line. The data transmission can be carried out in wired and wireless ways, based on the temperature and vibration data of the motor, and the risk of motor overheating and mechanical failure can be detected.

[0029] As a further solution of the present invention: in the step five, after the fault type is determined, a detailed fault report and precise repair suggestions are generated based on the empirical data and analysis algorithms in the fault detection and diagnosis model library. The fault report includes the type of fault, the time of occurrence and the scope of impact, and based on the repair suggestions, the corresponding repair program mechanical precision repair operation is started. During the repair process, the progress and effect of the repair are detected in real time. After the repair is completed, the motor is fully tested and verified to ensure that the motor can operate normally.

[0030] By adopting the above technical solution, compared with the prior art, the beneficial effects of the present invention are:

[0031] 1. The present invention can reduce the motor speed quickly in a very short time through the active short-circuit shutdown mode to achieve the function of rapid shutdown, and can avoid the problem of uncontrollable deceleration caused by natural shutdown. By adopting the ASC braking mode and a series of precise control steps, the problems of long shutdown time and uncontrollable deceleration in the traditional Free Wheeling shutdown mode are effectively solved. By establishing a mathematical relationship model between the motor speed and the control signal, the duty cycle of the control signal can be accurately calculated and adjusted according to the actual operating state and working condition of the motor, ensuring that the motor can quickly and smoothly enter the speed range suitable for shutdown. Compared with the traditional method relying on inertia natural deceleration, this greatly shortens the time from the running state to the stop of the motor;

[0032] 2. The present invention forms an efficient electromagnetic damping structure by specially connecting and combining specific phase windings of the motor, which quickly consumes the kinetic energy of the motor. By timely establishing electromagnetic damping, the operating state of the motor can be quickly stabilized, avoiding damage to the system due to unstable vibration, and ensuring the normal operation and safe use of the system. Through precise braking control and rapid shutdown, the inertial running time of the motor during the shutdown process is greatly reduced, thereby reducing the friction and wear of mechanical parts. In high-frequency start-stop application scenarios, this can significantly reduce the maintenance frequency and maintenance cost of the equipment. Through rapid shutdown, the time the motor is in the operating state is reduced, energy loss and heat generation are reduced, thereby effectively avoiding the occurrence of problems such as overheating. At the same time, precise braking control also reduces adverse effects such as electromagnetic interference to the surrounding environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1The figure is a schematic flow chart of a method for rapid motor shutdown in an embodiment of the present invention. DETAILED DESCRIPTION

[0034] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0035] The present invention provides a motor rapid shutdown method, comprising controlling the shutdown mode to stop at a fixed speed, closing three upper bridges of a three-phase bridge rectifier circuit, and simultaneously opening three lower bridges to realize active shutdown, adopting an ASC braking mode, and the specific operation steps of the motor rapid shutdown method are as follows:

[0036] Step 1: When the motor adopts the position sensorless control mode and receives the shutdown command, the motor speed is accurately controlled to the preset shutdown speed range using the closed-loop speed regulation technology, and the motor speed is calculated and adjusted according to the coefficient determined by the motor characteristics and the actual working conditions;

[0037] Step 2: Pre-configure the ASC braking parameters and strategies before the motor starts, and dynamically adjust the braking intensity and timing in real time according to the motor's operating status and load characteristics;

[0038] Step 3: When the motor speed increases abnormally and the system detects a serious fault signal, the ASC brake is immediately switched to a multi-phase conduction mode, and the specific phase windings of the motor are specially connected and combined according to a specific technical solution to form an efficient electromagnetic damping structure to quickly consume the kinetic energy of the motor;

[0039] Step 4: Build a real-time monitoring and data analysis system. The system can continuously detect the key parameters of the motor and transmit the data to the central processor in real time for analysis and processing. According to the real-time data, a separate mathematical model and algorithm are established to predict the operating status of the motor.

[0040] Step 5. Establish a fault monitoring and diagnosis model, introduce a large amount of historical fault data into the model library, monitor and record various fault types in real time, and quickly locate and analyze the fault when it occurs. Based on rich experience data and advanced analysis algorithms, provide detailed fault reports and accurate repair suggestions, and start the corresponding repair program according to the suggestions to perform accurate repair operations.

[0041] In one embodiment of the present invention: In step 1, a mathematical relationship model between the motor speed and the control signal is established, where the motor speed is marked as ω, the duty cycle of the control signal is d, and the load torque of the motor is T L, the moment of inertia of the motor is J. According to the dynamic equation and electrical equation of the motor, the following formula is obtained:

[0042] T e =K t ·i

[0043] Where K t is the torque constant of the motor, i is the phase current of the motor;

[0044] The equation of motion for the motor is:

[0045]

[0046] In the above formula, B ω Represents the friction torque term of the motor.

[0047] In one embodiment of the present invention: in combination with the above formula, the duty cycle of the control signal is adjusted according to the actual measured motor current and speed to control the speed of the motor. When a shutdown command is received, the duty cycle change Δd that needs to be adjusted is calculated based on the current motor speed and the target shutdown speed range, and the control algorithm is used to adjust the motor speed to control the motor speed within the preset shutdown speed range.

[0048] In one embodiment of the present invention: in step 2, before the motor is started, the initial parameters of the ASC braking are determined according to the rated parameters of the motor and the actual application scenario, and the initial conduction time of the ASC braking is t a , the initial off time is t b , according to the motor's inductance L, resistance R and motor speed n, the following formula is obtained:

[0049] τ=L / R

[0050] Among them, τ is the time constant of the calculation motor;

[0051] According to the initial conduction time t a According to the empirical formula t a =k1·τ, where k1 is a coefficient determined according to motor characteristics and actual working conditions, and the coefficient range is between 0.5-2;

[0052] According to the initial off time t b And it is determined according to the motor speed and load characteristics. The specific formula is as follows:

[0053]

[0054] Among them, is a coefficient determined according to actual conditions, and the coefficient range is between 0.1 and 1.

[0055] In one embodiment of the present invention: when the motor speed increases, the on-time t is reduced.a and increase the off time t b , when the motor load increases, increase the conduction time t a , in order to establish a neural network controller, which outputs the optimal ASC braking parameter adjustment according to the input motor operating state parameters and load characteristic parameters.

[0056] In one embodiment of the present invention: in step three, when the motor speed increases abnormally and the system detects a serious fault signal, the multi-phase conduction mode switching mechanism is immediately triggered, and two phases are selected for special connection according to the fault type and the operating status of the motor.

[0057] In one embodiment of the present invention: in step four, the key parameters of the motor include speed, current, temperature and vibration frequency, and the external environment includes air pressure and humidity. Based on historical data and real-time parameters, the performance change trend of the motor in the future is predicted, potential failure risks are discovered in advance, and corresponding countermeasures are taken in time to adjust and optimize.

[0058] In one embodiment of the present invention: in step four, a comprehensive sensor network is established to detect the key parameters of the motor in real time, and the data collected by the sensor is transmitted to the central processor in real time through the data transmission line. The data transmission can be carried out in wired and wireless ways, based on the temperature and vibration data of the motor, and the risk of motor overheating and mechanical failure is detected.

[0059] In one embodiment of the present invention: in step five, after the fault type is determined, a detailed fault report and precise repair suggestions are generated based on the empirical data and analysis algorithms in the fault detection and diagnosis model library. The fault report includes the type of fault, the time of occurrence, and the scope of impact. Based on the repair suggestions, the corresponding repair program mechanical precision repair operation is started. During the repair process, the progress and effect of the repair are detected in real time. After the repair is completed, the motor is fully tested and verified to ensure that the motor can operate normally.

[0060] Embodiment 1

[0061] On an automated production line for automobile parts, numerous motors drive various mechanical devices to complete different production tasks, such as conveyor motors for transporting materials and drive motors for stamping operations. These motors need to be started and stopped frequently to adapt to different production processes.

[0062] Various types of motors that meet the power requirements of the production line are used, equipped with a special controller to implement the motor rapid shutdown method of the present invention, and multiple sensors for monitoring key parameters of the motor are installed, including a speed sensor, a current sensor, a temperature sensor, and a vibration sensor. At the same time, a data transmission line is built to connect to the central processing unit, and the central processing unit uses a high-performance industrial computer;

[0063] According to the motor specifications and the working requirements of the production line, the relevant parameters of the motor fast stop method are set in the controller. According to the characteristics of the motor and the actual working conditions, the initial parameters of the ASC brake are determined, and the appropriate initial on-time and off-time are calculated based on the inductance, resistance and the speed range of the motor that usually runs on the production line.

[0064] When the production line needs a motor to stop working, the controller immediately starts the closed-loop speed regulation technology after receiving the shutdown command, monitors the motor speed in real time through the speed sensor, and adjusts the duty cycle of the control signal according to the established mathematical relationship model and the actual measured motor current, so that the motor speed quickly enters the preset shutdown speed range;

[0065] During the operation of the motor, the operating status and load characteristics of the motor are monitored in real time. When the motor load increases due to changes in the weight of the transported materials, the controller automatically increases the conduction time of the ASC brake according to the calculation results of the neural network controller to enhance the braking effect. When the motor speed fluctuates abnormally, the system quickly analyzes the cause. If the abnormal increase in the motor speed is caused by interference from other equipment on the production line, the ASC brake is immediately switched to the multi-phase conduction mode, and the specific phase windings of the motor are specially connected according to the preset plan to form an electromagnetic damping structure to quickly consume kinetic energy.

[0066] The real-time monitoring system built continuously collects key parameters such as the motor's speed, current, temperature, and vibration, and transmits them to the central processor in real time through the data transmission line. The central processor builds a mathematical model based on real-time data and historical data to predict the performance change trend of the motor in the future. According to the model, the motor may be at risk of overheating after a period of continuous high-load operation. The system issues an early warning and adjusts the work rhythm of the production line to give the motor appropriate rest time.

[0067] When a motor fails, the current sensor detects an abnormal increase in current, and the system immediately starts the fault monitoring and diagnosis model. It quickly locates and analyzes the fault based on the motor operating parameters and historical fault data, and determines that the fault type is a possible short circuit inside the motor. It then generates a detailed fault report, including the time the fault occurred, the scope of impact, and accurate repair suggestions. The repair program is automatically started based on the repair suggestions, and maintenance personnel use professional testing equipment and tools to perform accurate repair operations. During the repair process, the system monitors the repair progress and results in real time. After the repair is completed, the motor is fully tested to ensure that the motor can operate normally and be put back into production line operation.

[0068] Embodiment 2

[0069] In a wind farm, the motor of a wind turbine generator needs to frequently adjust its speed and shut down according to changes in wind speed. When the wind speed is too high or equipment maintenance is required, the motor must stop running quickly and safely to protect the power generation equipment and ensure the safety of personnel.

[0070] Large wind turbines and their supporting motors are equipped with controllers specially designed for wind power generation systems, which have the ability to resist strong wind interference and adapt to complex environments. High-precision sensors are installed at key parts of the motors to monitor parameters such as speed, current, temperature, and wind speed in the environment where the motors are located. Data transmission adopts a combination of wireless and wired methods to ensure stable data transmission even in harsh field environments.

[0071] Before the motor starts, the parameters and strategies of ASC braking are pre-configured according to the motor characteristics of the wind turbine and the local wind environment characteristics. The initial on-time and off-time of ASC braking are determined according to the rated power of the motor and the operation conditions at different wind speeds. When the wind speed is below 8 meters per second, a relatively short on-time and a long off-time are set to meet the motor shutdown requirements at lower wind speeds. When the wind speed exceeds 15m / s, the system automatically adjusts to a longer on-time and a shorter off-time according to the motor speed and load conditions calculated by the system to ensure rapid braking in strong wind environments.

[0072] When a shutdown command is received, whether it is an emergency shutdown due to excessive wind speed or a scheduled maintenance shutdown, the controller first uses closed-loop speed regulation technology to accurately adjust the duty cycle of the control signal based on the mathematical relationship model between the motor speed and the control signal, combined with the real-time monitored wind speed and motor speed data, so that the motor speed is quickly reduced to a safe shutdown speed range;

[0073] During the operation of the motor, various parameters of the motor and wind speed changes are monitored in real time. When the wind speed suddenly increases, causing the motor speed to increase abnormally, the system immediately switches the ASC brake to the multi-phase conduction mode. According to the pre-designed special connection scheme for the wind power generation system, the motor windings are connected to form a powerful electromagnetic damping, which quickly consumes the kinetic energy accumulated by the motor under the action of strong winds. Two phases of the three-phase winding of the motor are connected in series and then connected in parallel with the third phase winding. Through this special connection method, the motor speed can be reduced to a safe range in a short time.

[0074] The real-time monitoring and data analysis system built continuously collects the motor's operating data and environmental data such as wind speed. Based on historical data and real-time wind speed, motor speed and other parameters, a mathematical model is established to predict the performance change trend of the motor under different wind speed conditions. For example, according to the model, if the wind speed continues to increase in the future, it may cause an overload risk to the motor. The operating status of the motor can be adjusted in advance, the speed can be reduced or pre-shutdown measures can be taken;

[0075] When a motor fails, such as when the temperature sensor detects that the motor temperature is too high or the vibration sensor detects that the motor vibration is abnormal, the system immediately starts the fault monitoring and diagnosis model, quickly locates and analyzes the fault based on historical fault data and current operating parameters, and determines the fault type as abnormal vibration caused by motor bearing wear. A detailed fault report is generated, including the time of the fault, the scope of impact, and accurate repair suggestions. The repair program is automatically started based on the repair suggestions. Maintenance personnel carry professional tools and spare bearings to the wind turbine site for accurate repair operations. During the repair process, the repair progress and results can be monitored in real time through the remote monitoring system. After the repair is completed, the motor is fully tested and verified to ensure that the motor can operate normally and return to power generation.

[0076] Embodiment 3

[0077] In a precision CNC machine tool processing workshop, the motors of CNC machine tools require high-precision control and fast response capabilities to ensure the accuracy and quality of machined parts. During the processing, the motors need to be started and stopped frequently according to different processing steps, and must be able to stop running quickly and safely in the event of a fault or emergency;

[0078] A high-precision CNC machine tool and its supporting motor, a specially designed CNC system as a controller, an integrated motor rapid shutdown method of the present invention, a high-precision sensor installed on the motor to monitor the motor speed, current, temperature and vibration of the machine tool and other key parameters, and a high-speed wired network is used for data transmission to connect to a central control computer;

[0079] According to the processing requirements of CNC machine tools and the performance characteristics of motors, the relevant parameters of motor rapid shutdown are set in the CNC system. Before the motor is started, the parameters and strategies of ASC braking are pre-configured. According to different processing materials and cutting forces of tools, the initial on-time and off-time of ASC braking are determined. When processing materials with higher hardness, the on-time is appropriately increased to provide stronger braking torque to ensure that the motor can stop quickly during processing;

[0080] When the CNC machine tool receives a stop command, whether it is a stop after normal processing or due to a fault or emergency, the CNC system immediately starts the closed-loop speed regulation technology, monitors the motor speed and current in real time, and accurately adjusts the duty cycle of the control signal according to the established mathematical model and actual working conditions, so that the motor speed quickly enters the preset stop speed range. During fine processing, if an emergency stop is required, the system can adjust the control signal within milliseconds to quickly reduce the motor speed to a safe range to avoid damage to the processed parts;

[0081] During the operation of the motor, various parameters of the motor and the working status of the machine tool are monitored in real time. When the motor speed increases abnormally or the system detects a serious fault signal, when the tool breaks and the motor load changes suddenly, the ASC brake is immediately switched to the multi-phase conduction mode. According to the pre-designed special connection scheme for CNC machine tool motors, the motor windings are specially connected to form an electromagnetic damping structure to quickly consume the kinetic energy of the motor. At the same time, the CNC system adjusts the status of other parts of the machine tool according to real-time data and moves the tool to a safe position to prevent further damage.

[0082] The real-time monitoring and data analysis system built continuously collects various data of motors and machine tools, and transmits the data to the central control computer. Based on the historical processing data and real-time parameters, a mathematical model is established to predict the performance change trend of the motor under different processing procedures. According to the model, it is predicted that the motor may be at risk of overheating after a period of continuous processing. The processing parameters are adjusted in advance to reduce the motor load or suspend processing to let the motor cool down.

[0083] When a motor fails, such as when the current sensor detects abnormal current fluctuations or the temperature sensor detects that the motor temperature is too high, the system immediately starts the fault monitoring and diagnosis model, and quickly locates and analyzes the fault based on historical fault data and current operating parameters. When the fault type is determined to be an internal circuit fault in the motor, a detailed fault report is generated, including the time when the fault occurred, the scope of impact, and accurate repair suggestions. The repair program is automatically started based on the repair suggestions, and maintenance personnel use professional testing equipment and tools to perform accurate repair operations. During the repair process, the system monitors the repair progress and results in real time. After the repair is completed, the motor is fully tested and verified to ensure that the motor can operate normally and return to processing.

[0084] According to the above three groups of embodiments, it can be concluded that by quickly responding to abnormal conditions of the motor to ensure the stability and safety of the system, an efficient, reliable and economical motor operation and shutdown management method can be implemented as a whole.

[0085] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the scope of protection of the present invention.

[0086] In the description of the specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0087] The above contents are merely examples and explanations of the present invention. Various modifications or additions to the specific embodiments described or replacements in similar ways by technicians in the technical field shall fall within the protection scope of the present invention as long as they do not deviate from the invention or exceed the scope defined by the claims.

[0088] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for rapid motor shutdown, including controlling the shutdown mode to stop at a fixed speed, closing the three upper bridges of the three-phase bridge rectifier circuit, and opening the three lower bridges to realize active shutdown, using the ASC (Active Short Circuit) braking mode, characterized in that: The specific operation steps of the motor quick stop method are as follows: Step 1: When the motor adopts the position sensorless control mode and receives the stop command, the motor speed is calculated and adjusted according to the coefficient determined by the motor characteristics and the actual working conditions; Step 2: Pre-configure the ASC braking parameters and strategies before the motor starts, and dynamically adjust the braking intensity and timing in real time according to the motor's operating status and load characteristics; Step 3: When the motor speed increases abnormally and the system detects a serious fault signal, the ASC brake is immediately switched to a multi-phase conduction mode to quickly consume the kinetic energy of the motor; Step 4: Build a real-time monitoring and data analysis system to transmit data to the central processor in real time for analysis and processing, and predict the operating status of the motor; Step 5: Establish a fault monitoring and diagnosis model, introduce a large amount of historical fault data into the model library, monitor and record various fault types in real time, provide detailed fault reports and accurate repair suggestions, and start the corresponding repair program according to the suggestions to perform accurate repair operations.

2. A motor rapid shutdown method according to claim 1, characterized in that: In the step 1, a mathematical relationship model between the motor speed and the control signal is established, where the motor speed is marked as ω, the duty cycle of the control signal is d, and the load torque of the motor is T L , the moment of inertia of the motor is J. According to the dynamic equation and electrical equation of the motor, the following formula is obtained: T e =K t ·i Where K t is the torque constant of the motor, i is the phase current of the motor; The equation of motion for the motor is: In the above formula, B ω Represents the friction torque term of the motor.

3. A motor rapid shutdown method according to claim 2, characterized in that: Combined with the above formula, the duty cycle of the control signal is adjusted according to the actual measured motor current and speed to control the motor speed. When a shutdown command is received, the duty cycle change Δd that needs to be adjusted is calculated based on the current motor speed and the target shutdown speed range. Adjustments are made according to the control algorithm to control the motor speed within the preset shutdown speed range.

4. A motor rapid shutdown method according to claim 1, characterized in that: In step 2, before the motor is started, the initial parameters of the ASC brake are determined according to the rated parameters of the motor and the actual application scenario, and the initial conduction time of the ASC brake is set to t a , the initial off time is t b , according to the motor's inductance L, resistance R and motor speed n, the following formula is obtained: τ=L / R Among them, τ is the time constant of the calculation motor; According to the initial conduction time t a According to the empirical formula t a =k1·τ, where k1 is a coefficient determined according to motor characteristics and actual working conditions, and the coefficient range is between 0.5-2; According to the initial off time t b And it is determined according to the motor speed and load characteristics. The specific formula is as follows: Among them, is a coefficient determined according to actual conditions, and the coefficient range is between 0.1 and 1.

5. A motor rapid shutdown method according to claim 4, characterized in that: When the motor speed increases, the on-time t is reduced. a and increase the off time t b , when the motor load increases, increase the conduction time t a , in order to establish a neural network controller, which outputs the optimal ASC braking parameter adjustment according to the input motor operating state parameters and load characteristic parameters.

6. A motor rapid shutdown method according to claim 1, characterized in that: In step three, when the motor speed increases abnormally and the system detects a serious fault signal, the multi-phase conduction mode switching mechanism is immediately triggered, and two phases are selected for special connection according to the fault type and the running state of the motor.

7. A motor rapid shutdown method according to claim 1, characterized in that: In step 4, the key parameters of the motor include speed, current, temperature and vibration frequency, and the external environment includes air pressure and humidity. Based on historical data and real-time parameters, the performance change trend of the motor in the future is predicted, potential failure risks are discovered in advance, and corresponding countermeasures are taken in time to adjust and optimize.

8. A motor rapid shutdown method according to claim 1, characterized in that: In step 4, a comprehensive sensor network is established to detect the key parameters of the motor in real time, and the data collected by the sensor is transmitted to the central processor in real time through the data transmission line. The data transmission can be carried out in wired and wireless ways, based on the temperature and vibration data of the motor, and the risk of motor overheating and mechanical failure is detected.

9. A motor rapid shutdown method according to claim 1, characterized in that: In step five, after the fault type is determined, a detailed fault report and precise repair suggestions are generated based on the empirical data and analysis algorithms in the fault detection and diagnosis model library. The fault report includes the type of fault, the time of occurrence, and the scope of impact. Based on the repair suggestions, the corresponding repair program mechanical precision repair operation is started. During the repair process, the progress and effect of the repair are detected in real time. After the repair is completed, the motor is fully tested and verified to ensure that the motor can operate normally.

Images