A method suitable for time-sharing step-down starting of multiple 10kV motors

Abstract

The present application relates to the technical field of 10kV electrical system motor step-down starting, and discloses a method suitable for time-sharing step-down starting of multiple 10kV motors, which comprises the following steps: according to the instruction of a central control system, a movable intelligent starting module is automatically positioned and connected to a specified motor port, double identification and topology verification are carried out through physical ID and network logical position, before starting, dynamic thermal model is used to make a pre-judgment of starting temperature rise based on the current thermal load state of the module and the load characteristics of the target motor, and only when the predicted peak temperature is lower than the safety threshold value, the starting is allowed, after the starting is successful, the module is safely separated, and the thermal load state of the module is updated in real time to provide initial conditions for the next pre-judgment. Through the sharing mode of one machine for multiple uses, the equipment investment and maintenance cost are reduced, the pre-judgment mechanism before starting avoids the thermal damage of the equipment caused by continuous tasks, and the operation reliability of the system under high multiplexing is ensured.

Description

Technical Field

[0001] This invention relates to the field of reduced-voltage starting technology for 10kV electrical system motors, specifically a method for time-sharing reduced-voltage starting of multiple 10kV motors. Background Technology

[0002] In heavy industrial environments such as mines, ports, large manufacturing plants, and water treatment plants, high-power high-voltage motors are the core power units driving critical production equipment (such as large crushers, ball mills, conveyor belts, fans, and water pumps). Because high-voltage motors generate inrush currents of 5 to 8 times their rated current during direct starting, this massive current surge not only causes significant voltage drops in the power grid, affecting the stable operation of other equipment on the same grid, but also generates enormous electromagnetic and mechanical stresses on the motor's windings and the driven machinery, potentially leading to equipment damage and shortened service life. Therefore, equipping each high-voltage motor with a dedicated step-down starting device, such as a soft starter or frequency converter, has become standard practice in the industrial sector.

[0003] However, the currently prevalent technical solution is to equip each high-voltage motor with a fixed, one-to-one starter cabinet. While this fixed model of one motor and one cabinet can achieve basic starting functions, its inherent shortcomings are becoming increasingly apparent in the context of modern industrial production that pursues efficiency and economy. First, this model leads to huge asset investment and idle waste. As a functional device, the starting equipment's working time is limited to the brief moments of motor starting and stopping; for the vast majority of the motor's entire operating cycle, it is idle. For large enterprises with dozens or even hundreds of high-voltage motors, this means that they need to purchase, install, and maintain an equal number of expensive starter cabinets, resulting in extremely high initial investment and continuous maintenance costs, and extremely low asset utilization.

[0004] Secondly, the system's operational flexibility and reliability are severely constrained. Because the starter cabinet and motor are rigidly connected, a failure in the dedicated starter cabinet for a single motor will directly cause that critical equipment to stop, leading to an interruption of the entire production chain. Restoring production often requires complex and time-consuming electrical switching and bypass operations, or even replacing the entire starter cabinet, which not only prolongs downtime but also introduces operational risks to maintenance personnel. Furthermore, the numerous starter cabinets dispersed across a vast factory area significantly increase the complexity and workload of daily inspections and maintenance, reducing operational efficiency. This rigid configuration cannot meet the demands of modern industry for flexible equipment deployment, rapid response, and intelligent management, creating a contradiction between operating costs, asset efficiency, and production reliability. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a method for time-sharing reduced-voltage starting of multiple 10kV motors. This method solves the problems of risk of incorrect starting parameter settings due to reliance on manual operation, risk of thermal damage due to inaccurate equipment status judgment, and increased system complexity and high cost in order to avoid these risks when performing time-sharing reduced-voltage starting of multiple 10kV motors in existing technologies.

[0006] To solve the above-mentioned technical problems, the present invention provides a method for time-sharing reduced-voltage starting of multiple 10kV motors, comprising the following steps:

[0007] S1. A central control system receives a reduced-voltage start request for a 10kV motor.

[0008] S2. Move an intelligent mobile start module to a standardized fixed docking port associated with the feed circuit of the 10kV motor;

[0009] S3. The intelligent mobile startup module establishes an electrical and communication connection with the standardized fixed docking port, and completes identity recognition and configuration loading based on the communication connection, so that the intelligent mobile startup module is ready.

[0010] S4. Before performing the reduced-voltage startup, the intelligent mobile startup module performs a startup condition prediction.

[0011] S5. The intelligent mobile start module performs a reduced-voltage start on the 10kV motor according to the start feature package loaded in step S3.

[0012] S6. After the 10kV motor enters the running state, the intelligent mobile start module is disconnected from the standardized fixed docking port, and the status of the intelligent mobile start module itself is updated.

[0013] Preferably, in step S3, establishing the electrical connection and communication connection specifically involves:

[0014] A composite optoelectronic blind-mating connector is used to physically connect the intelligent mobile start-up module and the standardized fixed docking port to establish a high-voltage electrical path, and a fiber optic Ethernet link is established between the intelligent mobile start-up module and the central control system for data exchange between the intelligent mobile start-up module and the central control system.

[0015] In one specific embodiment, the identity recognition and configuration loading in step S3 includes:

[0016] The intelligent mobile startup module reads the identity ID stored in the RFID tag on the standardized fixed docking port through its built-in RFID reader;

[0017] The intelligent mobile startup module broadcasts its device identity information using a link layer discovery protocol running on the fiber optic Ethernet link;

[0018] The central control system combines the identity ID with the device identity information to determine the correctness of the connection topology, and retrieves the starting characteristic package that matches the 10kV motor from a database, and sends it to the intelligent mobile starting module via the fiber optic Ethernet link.

[0019] Furthermore, step S3 also includes a closed-loop verification step after loading the startup feature package:

[0020] The internal programmable logic controller of the intelligent mobile startup module performs a hash operation on the data content in the startup feature package other than the preset hash value to obtain a local hash value.

[0021] Compare the local hash value with the preset hash value in the startup feature package;

[0022] The fact that the two hash values ​​are consistent is a prerequisite for allowing the execution of step S4.

[0023] Preferably, the start-up condition prediction in step S4 specifically includes:

[0024] The internal programmable logic controller of the intelligent mobile startup module uses a dynamic thermal model embedded in it, combined with its own historical thermal load status and the load characteristic data in the startup characteristic package obtained from step S3, to predict the peak junction temperature of its internal power semiconductor device during this buck startup process.

[0025] The process of predicting the peak junction temperature can be iteratively calculated using the following thermal model:

[0026] ;

[0027] In the formula: Index of discrete simulation time steps ; : Index of the next discrete simulation time step; : No. Predicted junction temperature for each discrete simulation time step; : No. Instantaneous power consumption at each discrete simulation time step; : No. The discrete simulation time step is the power semiconductor device case temperature measured by a temperature sensor; Steady-state junction-to-case thermal resistance of power semiconductor devices; Equivalent heat capacity of power semiconductor devices; Simulation time step.

[0028] The instantaneous power consumption It can be calculated using the following formula:

[0029] ;

[0030] In the formula: Threshold voltage of power semiconductor devices; Dynamic on-resistance of power semiconductor devices; : No. The average current flowing through the power semiconductor device at each discrete simulation time step; : No. The effective value of the current flowing through the power semiconductor device at each discrete simulation time step.

[0031] In a preferred embodiment, after predicting the peak junction temperature, the method further includes the following steps:

[0032] Determine whether the predicted peak junction temperature is less than a preset safe temperature threshold.

[0033] If it is less than, then step S5 is allowed to be executed;

[0034] If the value is not less than the specified value, then step S5 is prohibited, and a request for delayed startup is sent to the central control system.

[0035] Furthermore, updating the state of the intelligent mobile startup module itself in step S6 includes:

[0036] The dynamic thermal model continuously calculates the natural cooling process of the junction temperature of the power semiconductor device based on ambient temperature and time, so as to update the historical thermal load state and provide the updated historical thermal load state when the start-up condition prediction is executed next time.

[0037] The natural cooling process of the junction temperature can be calculated by the following formula:

[0038] ;

[0039] In the formula: :go through Junction temperature after cooling over time; The temperature at the end of the last mission; Ambient temperature; Cooldown time since the last mission ended; The total thermal time constant of the intelligent mobile start-up module; : is the base of the natural logarithm; : is the exponential decay factor, a dimensionless coefficient between 0 and 1.

[0040] In one specific embodiment, the fiber optic Ethernet link utilizes virtual LAN technology and is divided into at least two mutually isolated logical channels:

[0041] A control channel is used to execute the transmission of the startup feature package in step S3;

[0042] A monitoring channel is used to upload real-time monitoring data in step S5.

[0043] Furthermore, the startup feature package includes:

[0044] Define the parameter points of the starting voltage or current curve, the maximum allowable current limit during the starting process, and the protection settings that match the 10kV motor.

[0045] As a preferred implementation of the above scheme, in step S5:

[0046] The intelligent mobile start-up module controls the start-up voltage or current according to the parameter points;

[0047] The intelligent mobile start-up module utilizes the maximum allowable current limit for overcurrent protection.

[0048] The intelligent mobile startup module uses the protection settings to monitor and protect against abnormal operating conditions during the startup process.

[0049] This invention provides a method for time-sharing reduced-voltage starting of multiple 10kV motors. It has the following beneficial effects:

[0050] 1. This invention uses an RFID reader to physically identify standardized fixed docking ports and combines a link layer discovery protocol to confirm the network topology, thereby binding the intelligent mobile start-up module with the 10kV motor to be started. Based on this binding relationship, the central control system sends a pre-verified start-up characteristic package from the database and ensures the integrity of the configuration data through hash value verification. This automated process replaces the traditional manual parameter setting and verification, avoiding incorrect configurations caused by operator negligence or misjudgment, and ensuring that the correct parameters are used for each start-up, thereby improving the safety and operational reliability of high-voltage motor start-up.

[0051] 2. Before performing a step-down start-up, this invention utilizes a dynamic thermal model embedded within the intelligent mobile start-up module. By combining the module's historical thermal load status with the load characteristics of the current task, the peak junction temperature of the core power semiconductor device during the upcoming start-up process is predicted. By comparing this predicted value with a safety threshold, the start-up operation is prohibited if the thermal condition does not permit it. This predictive protection mechanism avoids overheating damage to the device caused by heat accumulation due to continuous or high-load tasks, thus extending the service life of the intelligent mobile start-up module.

[0052] 3. This invention uses a single intelligent mobile starting module. By setting standardized fixed docking ports at multiple motors, it enables multiple 10kV motors to share starting resources in a time-sharing manner. It eliminates the need to equip each motor with an expensive fixed high-voltage starting cabinet, reducing the number of high-voltage equipment required and the space occupied, thus lowering the initial construction cost of the system. At the same time, the cyclical use of a single starting module achieves a utilization rate far higher than the total utilization rate of multiple fixed equipment. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the system architecture of one embodiment of the present invention;

[0054] Figure 2 This is a schematic diagram of the startup request response and physical location process according to an embodiment of the present invention;

[0055] Figure 3 This is a schematic diagram of an automated connection, identification, and configuration process according to an embodiment of the present invention;

[0056] Figure 4 This is a schematic diagram of the startup condition prediction process according to an embodiment of the present invention;

[0057] Figure 5 This is a block diagram of the buck startup execution control according to an embodiment of the present invention;

[0058] Figure 6 This is a schematic diagram of the separation and state update process according to an embodiment of the present invention.

[0059] Legend

[0060] 100. Central control system; 200. Intelligent mobile start-up module; 300. Standardized fixed docking port; 400. 10kV motor; 210. Internal programmable logic controller; 220. Power semiconductor device; 230. Temperature sensor; 240. RFID reader; 250. Composite optoelectronic blind mating connector; 310. High voltage electrical interface; 320. RFID tag; 330. Dating interface. Detailed Implementation

[0061] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0062] See attached document Figure 1 , attached Figure 1 This is a schematic diagram of a system architecture according to an embodiment of the present invention.

[0063] This invention provides a method for time-sharing reduced-voltage starting of multiple 10kV motors, which is executed in a specific system environment. The system may include: a central control system 100, an intelligent mobile starting module 200, at least one standardized fixed docking port 300, and at least one 10kV motor 400 associated with the standardized fixed docking port 300.

[0064] The central control system 100 is a data processing and command distribution unit. It communicates with other components in the system via an industrial Ethernet network. The central control system 100 contains a database that stores starting characteristic packages matched to each 10kV motor 400.

[0065] The intelligent mobile starter module 200 is a high-voltage electrical starter unit with mobility. It is configured to move between different standardized fixed docking ports 300 to provide time-sharing reduced-voltage starter functionality for multiple 10kV motors 400.

[0066] In one specific embodiment, the internal structure of the intelligent mobile start module 200 may include: an internal programmable logic controller 210, at least one power semiconductor device 220, a temperature sensor 230, an RFID reader 240, and a composite optoelectronic blind mating connector 250.

[0067] The internal programmable logic controller 210 is the control core of the intelligent mobile startup module 200. It is responsible for executing the logical steps of the method of the present invention, processing instructions and data from the central control system 100, and controlling the coordinated operation of various components within the module. A dynamic thermal model is stored in the memory of the internal programmable logic controller 210, which is used to calculate and predict the junction temperature of the power semiconductor device 220.

[0068] The power semiconductor device 220, such as a thyristor or insulated-gate bipolar transistor, is a power actuator that performs buck starting. Under the control of the internal programmable logic controller 210, it precisely controls the voltage or current output to the 10kV motor 400 by adjusting the conduction angle or the switching duty cycle.

[0069] Temperature sensor 230 is placed at a location that can reflect the thermal state of power semiconductor device 220, such as the surface of the device's housing. Its function is to measure and provide temperature data to the internal programmable logic controller 210 in real time as input parameters for dynamic thermal model calculations.

[0070] RFID reader 240 is used to transmit radio frequency signals and read the identity information fed back by RFID tags.

[0071] The composite optoelectronic blind mating connector 250 is an interface component that enables rapid connection between the intelligent mobile start-up module 200 and the standardized fixed docking port 300.

[0072] The standardized fixed docking port 300 is a passive interface device that is fixedly installed. Each standardized fixed docking port 300 is connected to the power supply circuit of a specific 10kV motor 400.

[0073] Its structure may include: a high-voltage electrical interface 310, an RFID tag 320, and a mating interface 330 that matches the composite optoelectronic blind mating connector 250.

[0074] The high-voltage electrical interface 310 is used to establish a high-voltage electrical path between the intelligent mobile starter module 200 and the 10kV motor 400 feeder circuit.

[0075] RFID tag 320 internally stores a unique ID to identify the port. Interface 330 serves as the corresponding connection component for composite optoelectronic blind-mating connector 250.

[0076] See attached document Figure 2 , attached Figure 2 This is a schematic diagram of the startup request response and physical location process according to an embodiment of the present invention.

[0077] The execution of the method of the present invention begins in step S1, that is, a central control system 100 receives a step-down start request for a 10kV motor 400.

[0078] In one specific embodiment, the reduced-voltage start-up request can be initiated by an operator on a human-machine interface connected to the central control system 100, or automatically issued by a higher-level manufacturing execution system according to a preset production plan.

[0079] The data structure of the reduced voltage start request contains a unique motor device identifier to precisely specify the target 10kV motor 400 that needs to be started.

[0080] Upon receiving the start request, the central control system 100 does not immediately forward the instruction. Instead, it first executes a series of verification logic. It accesses its internal database to verify the validity of the motor device identifier and queries the current status of the motor to confirm whether it is in standby mode, rather than running or under maintenance. Simultaneously, the central control system 100 also queries the current status of the intelligent mobile start module 200 to confirm whether it is in standby mode. Only when all verification conditions are met will the central control system 100 recognize the buck start request as a valid task.

[0081] After confirming the validity of the task, the central control system 100 will query its internal database again and retrieve the port identifier of the standardized fixed docking port 300 that is uniquely associated with it based on the motor equipment identifier.

[0082] Subsequently, the central control system 100 generates a movement command, the data packet of which contains a port identifier, and sends the movement command to the intelligent movement initiation module 200 via industrial Ethernet.

[0083] Next, the method proceeds to step S2. After receiving a movement command containing a target port identifier, the intelligent mobile initiation module 200 performs a physical positioning operation. In one embodiment, the intelligent mobile initiation module 200 is installed on the chassis of an automated guided vehicle or a rail-guided vehicle, and its internal navigation system parses the physical coordinates of the target standardized fixed docking port 300 from pre-stored factory map data based on the received port identifier.

[0084] The navigation system plans an optimal movement path based on the target coordinates and controls the chassis's drive system to travel along that path. During movement, the navigation system acquires its own position in real time through methods such as lidar, inertial navigation, or ground magnetic nails, and compares it with the planned path to form closed-loop control.

[0085] When the navigation system determines that it has reached the preset tolerance range of the target coordinates, the movement process is completed, and the intelligent movement start module 200 precisely stops in front of the target standardized fixed docking port 300, preparing for the next step of physical docking.

[0086] See attached document Figure 3 , attached Figure 3 This is a schematic diagram of an automated connection, identification, and configuration process according to an embodiment of the present invention.

[0087] After the intelligent mobile startup module 200 completes physical positioning, the method proceeds to step S3, which executes a series of automated connection, identification and configuration operations to make the intelligent mobile startup module 200 ready.

[0088] Step S3 first performs physical docking and link establishment. In one specific embodiment, a linear actuator on the intelligent mobile initiation module 200 drives the composite optoelectronic blind mating connector 250 on it to extend forward and engage with the docking interface 330 fixed on the standardized fixed docking port 300.

[0089] The composite optoelectronic blind mating connector 250 integrates high-voltage electrical contacts and fiber optic connectors.

[0090] During the engagement process, the internal guide pins ensure precise alignment. Once the docking is complete, the high-voltage electrical contact connects the power output terminal of the intelligent mobile start module 200 with the high-voltage electrical interface 310 of the standardized fixed docking port 300, thereby establishing a high-voltage electrical path to the 10kV motor 400 feed circuit.

[0091] At the same time, the fiber optic connector inside the composite optoelectronic blind-mating connector 250 also completes physical connection, establishing a physical layer fiber optic Ethernet link between the intelligent mobile start-up module 200 and the central control system 100. The fiber optic Ethernet link is logically divided into at least two mutually isolated channels using pre-configured virtual LAN technology:

[0092] One control channel is dedicated to transmitting critical data such as control commands and startup feature packages; one monitoring channel is used to upload real-time monitoring data in subsequent steps.

[0093] This separation ensures that the transmission of control commands is not interfered with by monitoring data traffic. Once the physical connection is complete, the identification and topology confirmation process begins immediately.

[0094] First, the internal programmable logic controller 210 of the intelligent mobile initiation module 200 activates its RFID reader 240, which emits a radio frequency field to power the passive RFID tag 320 on the standardized fixed docking port 300 and reads its internally stored unique identification ID. The identification ID represents the physical identity of the docking port, and the internal programmable logic controller 210 temporarily stores this physical identification ID.

[0095] Subsequently, after the data link layer of the fiber optic Ethernet link is established, the internal programmable logic controller 210 uses the link layer discovery protocol to broadcast an LLDP data frame containing its own device identity information (e.g., a unique MAC address) to the network.

[0096] The central control system 100 receives this LLDP data frame from the switch port it is connected to, thereby learning the network logical location currently connected to the intelligent mobile startup module 200. The central control system 100 then performs a strict topology check, comparing the physical identity ID received from the intelligent mobile startup module 200 with the network logical location it learned from LLDP.

[0097] The central control system 100 has a pre-stored mapping table in its database, which precisely defines the correct network logical location corresponding to each physical identity ID. Only when the two match perfectly does the central control system 100 confirm that the intelligent mobile startup module 200 is indeed connected to the correct predetermined port, and the connection topology is confirmed as valid.

[0098] After the topology is confirmed to be valid, the process of issuing and verifying the startup characteristic package begins. The central control system 100 uses the confirmed physical identity ID as an index to retrieve the startup characteristic package that perfectly matches the 10kV motor 400 to be started from its internal database.

[0099] This startup features package is a structured data collection, the contents of which include at least:

[0100] A set of parameter points for defining the starting voltage or current curve, a maximum allowable current limit for overcurrent protection during startup, a set of protection settings that match the motor, and a preset hash value obtained by hashing all the aforementioned data.

[0101] The reason why the start-up characteristic package needs to be precisely matched to each 10kV motor 400 is that different types or specifications of motors have significantly different load characteristics.

[0102] For example, fan loads have a large moment of inertia, requiring a longer acceleration time and a relatively gentle voltage ramp; while the starting torque of pump loads is proportional to the square of the rotational speed, and their starting current curve is different from that of fans.

[0103] Therefore, customizing a starting characteristic package for each motor, including the optimal starting curve and precise protection settings, is the technical foundation for achieving efficient and safe starting of different loads.

[0104] The central control system 100 sends the startup feature packet to the intelligent mobile startup module 200 through the control channel. After receiving the data packet, the internal programmable logic controller 210 of the intelligent mobile startup module 200 performs a closed-loop verification. It extracts all data content in the data packet except for the preset hash value, and uses the same hash algorithm (e.g., SHA-256) as the central control system 100 to calculate this part of the content to generate a local hash value.

[0105] Finally, the internal programmable logic controller 210 compares the generated local hash value with the preset hash value carried in the data packet. If the two hash values ​​match exactly, it proves that no errors or tampering occurred during the transmission of the startup feature packet, the configuration was successfully loaded, and the intelligent mobile startup module 200 enters the ready state, waiting to execute the next instruction.

[0106] If there is a discrepancy, the configuration loading is considered to have failed, and the module will send an error report to the central control system 100 and terminate the startup process.

[0107] See attached document Figure 4 , attached Figure 4 This is a schematic diagram of the start-up condition prediction process according to an embodiment of the present invention.

[0108] After successfully loading and verifying the startup feature package in step S3, the method proceeds to step S4 to perform a startup condition prediction based on the dynamic thermal model.

[0109] Step S4 is automatically initiated by the internal programmable logic controller 210 of the intelligent mobile startup module 200. Its purpose is to calculate and evaluate, through pure digital simulation, whether the upcoming buck startup process will cause overheating risk to the power semiconductor device 220 before the actual application of high voltage.

[0110] The prediction process begins with initialization. The internal programmable logic controller 210 reads the current historical thermal load state from its internal memory; this historical thermal load state is the initial junction temperature of the power semiconductor device 220 at the start of the simulation. The initial junction temperature This result is continuously calculated and updated by the dynamic thermal model based on cooling time and ambient temperature after the last task ended. Simultaneously, the controller reads the current device case temperature via temperature sensor 230. .

[0111] In addition, the controller extracts the load characteristic data defined for this task from the newly loaded startup characteristic package. The load characteristic data is specifically represented by an expected current curve describing the change of motor current over time throughout the startup process. .

[0112] Subsequently, the internal programmable logic controller 210 performs a discrete-time iterative simulation, which will determine the expected total startup time. Divided into A time step of equal length .

[0113] For from arrive At each time step, the controller performs the following calculations:

[0114] First, based on the expected current curve Calculate the first Average current within each discrete simulation time step and the effective value of current .

[0115] Then, using these two current values, the instantaneous power consumption of the power semiconductor device 220 during this time step is calculated using the following formula. :

[0116] ;

[0117] In the formula: This is the threshold voltage for power semiconductor devices. The dynamic on-resistance of the device is one of the two inherent electrical parameters obtained from the device datasheet and embedded in the controller. : No. The average current flowing through the power semiconductor device at each discrete simulation time step; : No. The effective value of the current flowing through the power semiconductor device at each discrete simulation time step.

[0118] Next, the controller uses its fixed dynamic thermal model to calculate the next discrete simulation time step using the following formula. Initial predicted junction temperature :

[0119] ;

[0120] In the formula: This is the initial junction temperature. ; The steady-state junction-to-case thermal resistance of the device, The equivalent heat capacity of the device is one of the two intrinsic physical parameters of the device; during the simulation, It can be determined by the initial shell temperature An approximate substitution is used because, during the brief startup period, the device case temperature changes more slowly than the junction temperature; the controller records the calculated values ​​in each iteration. ; Index of discrete simulation time steps ; : Index of the next discrete simulation time step; : No. Predicted junction temperature for each discrete simulation time step; : No. Instantaneous power consumption at each discrete simulation time step; Simulation time step.

[0121] After completing all After iterative calculations at each time step, the internal programmable logic controller 210 obtains a complete predicted junction temperature curve. The controller iterates through all temperature points on this curve and finds the maximum value, which is the predicted peak junction temperature for this startup process. .

[0122] Finally, a safety decision is made. The internal programmable logic controller 210 calculates the predicted peak junction temperature. It is compared with a preset safe temperature threshold (e.g., 125°C) stored internally. If If the temperature is below the safe temperature threshold, the controller determines that the start-up condition is met and allows execution of subsequent step S5. If the temperature is not lower than the safe temperature threshold, the controller determines that there is an overheating risk, prohibits the start-up, and immediately sends a delayed start request to the central control system 100 through the control channel of the fiber optic Ethernet link. The delayed start request may include the predicted peak junction temperature data for the system to make further decisions.

[0123] See attached document Figure 5 , attached Figure 5 This is a control block diagram for buck startup execution according to an embodiment of the present invention.

[0124] Once the startup conditions in step S4 are met, the central control system 100 sends a startup command to the intelligent mobile startup module 200.

[0125] Upon receiving the start command, the method proceeds to step S5, performing a complete reduced-voltage start on the 10kV motor 400. The reduced-voltage start process is implemented by the internal programmable logic controller 210 of the intelligent mobile start module 200, based on the loaded start characteristic package, through three parallel control and protection logics.

[0126] The first logic is closed-loop tracking control of the startup curve. The internal programmable logic controller 210 extracts a series of parameter points from the startup characteristic package. These parameter points together define an ideal startup voltage or current curve that varies with time, i.e., the target curve. .

[0127] The controller outputs the target curve value at a fixed high-frequency clock cycle. As a set value, the actual voltage or current value output to the motor is also collected by the sensor. As a feedback value.

[0128] An internal PID (proportional, integral, derivative) or PI (proportional, integral) controller adjusts the input based on the error between the setpoint and the feedback value. It performs calculations and generates a control signal.

[0129] In one specific embodiment, the power semiconductor device 220 is a group of anti-parallel thyristors. In this case, the control signal output by the PID or PI regulator is directly converted into the phase delay angle of the trigger pulse for this group of thyristors. By precisely adjusting the magnitude of this phase delay angle, the conduction time of the thyristors in each AC cycle can be controlled, thereby achieving continuous and smooth regulation of the effective value of the AC voltage output to the 10kV motor 400. The control signal is used to adjust the phase angle of the trigger pulse for the power semiconductor device 220 (e.g., the thyristor) in real time, thereby precisely controlling its conduction level, so that the actual output voltage or current can smoothly and accurately follow the preset target curve, achieving soft start of the motor.

[0130] The second logic is rapid protection against transient overcurrent. During the entire startup process, the internal programmable logic controller 210 continuously monitors the actual current flowing through the power semiconductor device 220 at a frequency much higher than that of the main control cycle through a high-speed sampling circuit.

[0131] The controller compares each sampled instantaneous current value with the maximum allowable current limit defined in the startup feature package. This comparison operation is performed with a very high priority, for example, through a hardware comparator or a dedicated interrupt service routine.

[0132] Once the detected instantaneous current value exceeds the limit, the controller will immediately execute hardware-level protection without any delay, instantly blocking all trigger pulses to the power semiconductor device 220. This action can cut off the current path within a microsecond, thereby providing the fastest short-circuit or stall overcurrent protection for the starting module itself and the downstream motor.

[0133] The third logic is based on abnormal operating condition monitoring using protection settings. In addition to instantaneous overcurrent protection, the internal programmable logic controller 210 also uses other protection settings provided in the startup feature package to monitor various abnormal operating conditions that may occur during startup.

[0134] For example, the controller monitors the imbalance of the three-phase current. If the imbalance exceeds the threshold set in the protection settings, it is determined that a phase loss or inter-turn short circuit fault has occurred.

[0135] For example, the controller will accumulate the start-up time. If the start-up time exceeds the maximum start-up time set in the protection settings and the motor current still has not dropped to the normal operating level, it will be judged as start-up timeout or overload.

[0136] When any abnormal operating condition defined by the protection setting is triggered, the controller will execute a preset, safe shutdown procedure and generate a code containing the specific fault type, which will be uploaded to the central control system 100 through the monitoring channel of the fiber optic Ethernet link for fault diagnosis and recording.

[0137] While executing all the above control and protection logic, the internal programmable logic controller 210 will also continuously upload all the key real-time data collected, including three-phase voltage, three-phase current, case temperature of power semiconductor device 220, and current operating status, to the central control system 100 through the monitoring channel to achieve transparent monitoring and data traceability of the entire startup process.

[0138] See attached document Figure 6 , attached Figure 6 This is a schematic diagram of the separation and state update process according to an embodiment of the present invention.

[0139] Once the 10kV motor 400 completes its startup process and enters a stable power frequency operating state, the method proceeds to step S6, where the intelligent mobile startup module 200 is separated and its own status is updated.

[0140] The trigger condition for step S6 is that the internal programmable logic controller 210 determines that the startup process has successfully ended. In a specific embodiment, the determination is based on the following: the motor current monitored by the controller in real time reaches its peak and then drops steadily, and remains near a stable operating current value lower than the rated current for a preset period of time (e.g., 2 seconds). This indicates that the motor has passed the startup stage and entered a self-sustaining operation state.

[0141] After confirming successful startup, the intelligent mobile startup module 200, in coordination with the central control system 100, executes a safe electrical disconnection procedure. First, the internal programmable logic controller 210 sends a startup completion signal to the central control system 100 via the control channel.

[0142] The central control system 100 then sends a command to the power distribution system to close the bypass vacuum contactor located on the main power supply circuit of the 10kV motor 400. After confirming that the bypass vacuum contactor has been reliably closed, that is, the 10kV motor 400 is directly powered by the grid, the central control system 100 returns a command to the intelligent mobile start module 200 to allow disconnection.

[0143] Upon receiving the command to disconnect, the internal programmable logic controller 210 first disconnects its internal power output contactor, completely electrically isolating itself from the high-voltage circuit. After completing the electrical isolation, it performs physical disconnection.

[0144] The internal programmable logic controller 210 controls its linear actuator to move in the reverse direction, causing the composite optoelectronic blind-mating connector 250 to smoothly detach from the mating interface 330 of the standardized fixed mating port 300. At this point, the physical and communication connections between the intelligent mobile start-up module 200 and the 10kV motor 400 are completely disconnected, allowing it to move to the next task location or return to the standby area.

[0145] The moment electrical isolation from the high-voltage circuit is achieved, the internal programmable logic controller 210 of the intelligent mobile start module 200 immediately begins to update its historical thermal load status.

[0146] The updating of historical thermal load status is a continuous background computation task whose purpose is to accurately track the junction temperature changes of the power semiconductor device 220 during natural cooling, so as to provide an accurate initial temperature condition for the next execution of start-up condition prediction.

[0147] The updating process of historical heat load status is based on its internally solidified dynamic thermal model, calculated using the following natural cooling mathematical model:

[0148] ;

[0149] In the formula: :go through After cooling, the junction temperature of the power semiconductor device 220 is calculated at the current moment; The final junction temperature recorded or calculated at the moment when the power semiconductor device 220 stops carrying current at the end of the last startup task; The internal ambient temperature of the module is measured in real time by the temperature sensor 230 installed inside the intelligent mobile start-up module 200;

[0150] : The cumulative cooldown time since the last time the task ended; this value is provided by the internal timer of the internal programmable logic controller 210. The total thermal time constant of the intelligent mobile startup module 200 is a fixed value that reflects the heat dissipation rate of the entire module from junction to environment and is determined in advance through experimental calibration or thermal simulation. : is the base of the natural logarithm; : is the exponential decay factor, a dimensionless coefficient between 0 and 1.

[0151] The internal programmable logic controller 210 performs this calculation cyclically at a fixed time interval (e.g., once per second), continuously using the newly calculated... The value overwrites the junction temperature state stored in memory. Therefore, regardless of whether the intelligent mobile startup module 200 is in the process of moving or in standby mode, the historical heat load state stored inside it is always dynamically updated, reflecting the current actual thermal state of the junction temperature value.

[0152] To further illustrate the technical solution of the present invention, a specific application scenario embodiment will be described below.

[0153] See attached document Figure 1 Suppose an industrial scenario includes a central control system 100, a standby intelligent mobile start-up module 200, and several 10kV motors 400 that need to be started in shifts, such as a high-pressure water pump, an aerator blower, and a sludge compressor. Each motor is equipped with its own dedicated standardized fixed docking port 300.

[0154] Since the intelligent mobile startup module 200 has been in standby mode for a long time, the initial junction temperature of the power semiconductor device 220 recorded by its internal dynamic thermal model has reached the same level as the internal ambient temperature of the intelligent mobile startup module 200, which is 25°C.

[0155] Task 1: Start the high-pressure water pump.

[0156] The execution of this method begins when the central control system 100 receives a request to start a high-pressure water pump (as the first target 10kV motor 400). After system verification, the task is confirmed to be valid, and a movement command containing the physical coordinates of its corresponding standardized fixed docking port 300 is sent to the intelligent mobile start-up module 200. The intelligent mobile start-up module 200 automatically navigates and precisely docks at the standardized fixed docking port 300 according to the movement command.

[0157] Subsequently, the module executes step S3, where the composite optoelectronic blind mating connector 250 completes the mating with the interface 330 of the port, establishing a high-voltage electrical path and a fiber optic Ethernet link. The RFID reader 240 reads the unique ID of the RFID tag 320 on the standardized fixed mating port 300, and at the same time, the link layer discovery protocol confirms the network connection location of the module.

[0158] After verifying the topology, the central control system 100 retrieves the startup characteristic package specifically configured for this high-pressure water pump from the database and sends it out through the control channel. Upon receiving the package, the intelligent mobile startup module 200 performs a hash operation on the data within the package and compares the result with the hash value already present in the package. Since they match, the configuration is successfully loaded.

[0159] Next, step S4 is executed to predict the startup conditions. The internal programmable logic controller 210 uses 25°C as the initial junction temperature and performs a discrete-time simulation using the expected current curve defined in the startup characteristic package. After iterative calculation, the predicted peak junction temperature of this startup process is 85°C. Since 85°C is lower than the preset safe temperature threshold of 125°C, the prediction is passed.

[0160] The central control system 100 then issues an execution command, and the intelligent mobile start module 200 enters step S5. Its internal programmable logic controller 210 precisely controls the output of the power semiconductor device 220 according to the parameter points in the start characteristic package, and performs a smooth pressure reduction start on the high-pressure water pump.

[0161] After the high-pressure water pump reaches stable operation, the intelligent mobile start module 200 executes step S6. After the bypass contactor closes, the intelligent mobile start module 200 is safely electrically isolated and physically separated from the standardized fixed docking port 300. At the moment of electrical isolation, the controller records the final junction temperature of the power semiconductor device 220 as 90°C and uses this as the initial value to continuously calculate and update the junction temperature state stored internally based on the ambient temperature and cooling time.

[0162] Task 2: Attempt to start the sludge compressor:

[0163] Fifteen minutes after completing the previous task, the central control system 100 received a request to start another motor with more stringent load characteristics, namely the sludge compressor (as the second target 10kV motor 400).

[0164] At this time, the dynamic thermal model inside the intelligent mobile startup module 200 has updated the junction temperature of the power semiconductor device 220 stored inside it from 90°C to 55°C through 15 minutes of natural cooling calculation.

[0165] The intelligent mobile start-up module 200 receives the instruction and moves to its corresponding standardized fixed docking port 300, repeating the automated connection and identification process of step S3. This time, the central control system 100 issues a start-up characteristic package specially configured for the sludge compressor. The load characteristic data in the characteristic package reflects that it requires a larger and more continuous current for start-up.

[0166] The intelligent mobile startup module 200 then executes step S4 again to make a prediction. Unlike the previous one, this time the initial junction temperature of the simulation is no longer 25℃, but has been updated to the current thermal state of 55℃. The internal programmable logic controller 210 combines the initial junction temperature of 55℃ and the high load data in the new startup feature package to perform iterative calculations, and finally obtains a predicted peak junction temperature of 130℃.

[0167] When making a safety decision, the programmable logic controller 210 compares the predicted temperature of 130°C with the safe temperature threshold of 125°C. Since the predicted value exceeds the threshold, the programmable logic controller 210 determines that there is a risk of overheating during this startup.

[0168] Therefore, startup is disabled, and the intelligent mobile startup module 200 does not proceed to step S5. Instead, it immediately sends a delayed startup request containing predicted temperature data to the central control system 100. Based on this, the central control system 100 notifies the operator that startup can only be attempted again after the intelligent mobile startup module 200 has further cooled down, thus effectively avoiding thermal damage caused by continuous operation.

Claims

1. A method for time-sharing reduced-voltage starting of multiple 10kV motors, characterized in that, Includes the following steps: S1. A central control system receives a reduced-voltage start request for a 10kV motor. S2. Move an intelligent mobile start module to a standardized fixed docking port associated with the feed circuit of the 10kV motor; S3. The intelligent mobile startup module establishes an electrical and communication connection with the standardized fixed docking port, and completes identity recognition and configuration loading based on the communication connection, so that the intelligent mobile startup module is ready. S4. Before performing the reduced-voltage startup, the intelligent mobile startup module performs a startup condition prediction. S5. The intelligent mobile start module performs a reduced-voltage start on the 10kV motor according to the start feature package loaded in step S3. S6. After the 10kV motor enters the running state, the intelligent mobile start module is disconnected from the standardized fixed docking port, and the status of the intelligent mobile start module itself is updated.

2. The method for time-sharing reduced-voltage starting of multiple 10kV motors according to claim 1, characterized in that, The establishment of electrical and communication connections in step S3 specifically refers to: A composite optoelectronic blind-mating connector is used to physically connect the intelligent mobile start-up module and the standardized fixed docking port to establish a high-voltage electrical path, and a fiber optic Ethernet link is established between the intelligent mobile start-up module and the central control system for data exchange between the intelligent mobile start-up module and the central control system.

3. The method for time-sharing reduced-voltage starting of multiple 10kV motors according to claim 2, characterized in that, The identity recognition and configuration loading in step S3 includes: The intelligent mobile startup module reads the identity ID stored in the RFID tag on the standardized fixed docking port through its built-in RFID reader; The intelligent mobile startup module broadcasts its device identity information using a link layer discovery protocol running on the fiber optic Ethernet link; The central control system combines the identity ID with the device identity information to determine the correctness of the connection topology, and retrieves the starting characteristic package that matches the 10kV motor from a database, and sends it to the intelligent mobile starting module via the fiber optic Ethernet link.

4. The method for time-sharing reduced-voltage starting of multiple 10kV motors according to claim 3, characterized in that, Step S3 also includes a closed-loop verification step after loading the startup feature package: The internal programmable logic controller of the intelligent mobile startup module performs a hash operation on the data content in the startup feature package other than the preset hash value to obtain a local hash value. Compare the local hash value with the preset hash value in the startup feature package; The two hash values ​​must match for step S4 to be allowed to proceed.

5. The method for time-sharing reduced-voltage starting of multiple 10kV motors according to claim 1, characterized in that, The specific steps for predicting the start-up conditions in step S4 are as follows: The internal programmable logic controller of the intelligent mobile startup module uses a dynamic thermal model embedded in it, combined with its own historical thermal load status and the load characteristic data in the startup characteristic package obtained from step S3, to predict the peak junction temperature of its internal power semiconductor device during this buck startup process.

6. A method for time-sharing reduced-voltage starting of multiple 10kV motors according to claim 5, characterized in that, After predicting the peak junction temperature, the following steps are also included: Determine whether the predicted peak junction temperature is less than a preset safe temperature threshold. If it is less than, then step S5 is allowed to be executed; If the value is not less than the specified value, step S5 is prohibited, and a request for delayed startup is sent to the central control system.

7. A method for time-sharing reduced-voltage starting of multiple 10kV motors according to claim 5, characterized in that, Step S6, which involves updating the state of the intelligent mobile startup module itself, includes: The dynamic thermal model continuously calculates the natural cooling process of the junction temperature of the power semiconductor device based on ambient temperature and time, so as to update the historical thermal load state and provide the updated historical thermal load state when the start-up condition prediction is executed next time.

8. A method for time-sharing reduced-voltage starting of multiple 10kV motors according to claim 3, characterized in that, The fiber optic Ethernet link utilizes virtual LAN technology and is divided into at least two mutually isolated logical channels: A control channel is used to execute the transmission of the startup feature package in step S3; A monitoring channel is used to upload real-time monitoring data in step S5.

9. A method for time-sharing reduced-voltage starting of multiple 10kV motors according to claim 3, characterized in that, The startup feature package includes: Define the parameter points of the starting voltage or current curve, the maximum allowable current limit during the starting process, and the protection settings that match the 10kV motor.

10. A method for time-sharing reduced-voltage starting of multiple 10kV motors according to claim 9, characterized in that, In step S5: The intelligent mobile start-up module controls the start-up voltage or current according to the parameter points; The intelligent mobile start-up module utilizes the maximum allowable current limit for overcurrent protection. The intelligent mobile startup module uses the protection settings to monitor and protect against abnormal operating conditions during the startup process.

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