Motor over-temperature self-restoring protector

Abstract

The application discloses a motor over-temperature self-recovery protector and belongs to the technical field of motor protection, comprising a shell, a temperature acquisition module, a control module, an execution module, a power module, a pre-warning module and a data recording module, wherein each module is integrated in the shell, and the shell is fixedly connected with a motor shell; the temperature acquisition module is used for collecting real-time temperatures of motor windings and the shell; the control module receives temperature signals and generates corresponding control instructions; the execution module receives the control instructions and realizes the cutting-off and self-recovery of a motor loop; the power module supplies power for each module; the pre-warning module sends graded pre-warning signals; and the data recording module records temperature data and fault information.The motor over-temperature self-recovery protector is used to realize the accurate monitoring of motor winding temperatures, has the functions of over-temperature pre-warning, fault recording and feedback, improves the safety and reliability of motor operation, reduces maintenance costs and is suitable for the use requirements of different types and different power motors.

Description

Technical Field

[0001] This invention relates to the field of motor protection technology, and in particular to a motor over-temperature self-resetting protector. Background Technology

[0002] During long-term operation, motors are prone to sudden increases in internal temperature due to abnormal conditions such as overload, stall, poor heat dissipation, excessively high ambient temperature, or short circuit in the windings. If protective measures are not taken in time, it can cause aging and burnout of the motor winding insulation, or even fire and other safety accidents, seriously affecting the service life of the motor and the safety of equipment operation.

[0003] Currently, existing motor over-temperature protection technologies are mainly divided into three categories: First, PTC type protectors, which achieve protection based on the resistance change characteristics of positive temperature coefficient thermistors. However, they have drawbacks such as fixed protection thresholds, easy Curie point drift with long-term use, and high power consumption in high-current scenarios. Moreover, they can only achieve single temperature threshold protection and cannot adapt to the differentiated needs of different motors. Second, bimetallic strip protectors, which rely on the difference in thermal expansion and contraction of metal to push the contacts to open. They have a slow response speed (seconds) and low protection accuracy (temperature difference ±5℃). Frequent operation can easily lead to metal fatigue failure. Some models cannot achieve automatic recovery and require manual reset. Third, electronic protectors, which achieve accurate monitoring through sensors and MCUs. However, they are expensive, require an external power supply, are sensitive to electromagnetic interference, and most models require manual reset or external signal triggering recovery, making them unsuitable for unattended scenarios in harsh environments.

[0004] Furthermore, in existing technologies, some protectors only monitor the surface temperature of the motor, resulting in a lag in temperature conduction and an inability to accurately reflect the actual temperature of the motor windings. Some self-resetting protectors tend to restart frequently after the temperature recovers, further damaging the motor. Simultaneously, most protectors lack fault warning functions, failing to anticipate over-temperature risks in advance, and lack the ability to record and feedback temperature and fault information, hindering subsequent fault diagnosis and motor operation and maintenance. Therefore, developing a motor over-temperature self-resetting protector that is fast-responding, provides accurate protection, has reliable self-resetting capabilities, is highly adaptable, and possesses both warning and fault recording functions is crucial to addressing the pain points of existing technologies. Summary of the Invention

[0005] The purpose of this invention is to provide a motor over-temperature self-recovery protector that enables accurate monitoring of motor winding temperature, while also providing over-temperature warning, fault recording and feedback functions, thereby improving the safety and reliability of motor operation, reducing maintenance costs, and adapting to the usage needs of different types and power motors.

[0006] To achieve the above objectives, the present invention provides a motor over-temperature self-recovery protector, comprising a housing, a temperature acquisition module, a control module, an execution module, a power supply module, an early warning module, and a data recording module, wherein each module is integrated inside the housing, and the housing is fixedly connected to the motor housing; The temperature acquisition module is used to acquire the real-time temperature of the motor windings and housing, and output a temperature signal; the control module receives the temperature signal from the temperature acquisition module, presets three temperature thresholds and performs logical judgments to generate corresponding control commands; the execution module receives the control commands from the control module to realize the disconnection and self-recovery of the motor circuit; the power supply module supplies power to each module; the early warning module receives the commands from the control module and issues graded early warning signals; the data recording module records temperature data and fault information.

[0007] Preferably, the temperature acquisition module includes a built-in acquisition unit and an external acquisition unit. The built-in acquisition unit is a PT100 platinum resistance sensor that extends into the motor windings, with a measurement range of -50℃ to 200℃ and a measurement accuracy of ±0.5℃. The external acquisition unit is an NTC thermistor sensor that is fixed on the thermally conductive silicone layer on the inner wall of the housing and fits tightly against the motor housing. It has a measurement range of -40℃ to 150℃ and a measurement accuracy of ±1℃. As a redundant backup of the built-in acquisition unit, it can automatically switch operation.

[0008] Preferably, the temperature acquisition module is further provided with a signal filtering unit to filter electromagnetic interference signals during the temperature acquisition process and improve the stability of the acquired signal.

[0009] Preferably, the control module uses an STM32 series microcontroller, which integrates an A / D conversion unit, a logic judgment unit, a threshold adjustment unit, a fault self-test unit, and an anti-shake unit; The A / D conversion unit converts the analog temperature signal output by the temperature acquisition module into a digital signal; the logic judgment unit presets a warning threshold T1, a protection threshold T2, and an emergency protection threshold T3, where T1 < T2 < T3, and compares the temperature data with the preset thresholds in real time to generate control commands; the threshold adjustment unit can flexibly adjust the values ​​of T1, T2, and T3 via a hidden adjustment knob or a host computer interface, with adjustment ranges of T1 40℃~80℃, T2 80℃~120℃, and T3 120℃~150℃; the fault self-test unit monitors the working status of each module in real time and records the fault type; the anti-shake unit can adjust the anti-shake time, ranging from 1 to 5 seconds, to avoid malfunctions of the execution module.

[0010] Preferably, the execution module includes a resettable fuse (PPTC), a high-temperature DC relay, and a MOSFET drive circuit. The resettable fuse and the relay are connected in series in the main circuit of the motor. The MOSFET drive circuit connects the control module and the high-temperature DC relay, and the response time is ≤50ms. When the motor temperature reaches the protection threshold T2, the resettable fuse is in a high-resistance state, the high-temperature DC relay is disconnected, and the motor main circuit is doubly cut off; when the temperature drops below the warning threshold T1, the resettable fuse automatically returns to a low-resistance state, the high-temperature DC relay is closed, and the motor circuit is self-restored without the need for manual reset or component replacement.

[0011] Preferably, the power module adopts a dual power supply mode, including a main power supply and a backup power supply; the main power supply is an AC / DC power module with an input voltage range of AC 220V / DC 12V~48V, and outputs DC 5V and DC 12V, which are used to power the control system and relays, respectively; the backup power supply is a built-in rechargeable lithium battery with a capacity of not less than 1000mAh, which automatically switches when the main power supply is interrupted, and the backup power supply has a battery life of ≥24h.

[0012] Preferably, the warning module includes a three-color LED indicator and a buzzer, both of which are located on the top of the housing. The three-color LED indicator corresponds to three working states: solid green for normal operation, flashing yellow for over-temperature warning, and flashing or solid red for over-temperature, emergency over-temperature, or fault conditions. The buzzer has a volume ≥80dB and only sounds during over-temperature, emergency over-temperature, and module fault conditions. It can be turned off by a mute button, which is integrated into the side surface of the buzzer.

[0013] Preferably, the data recording module includes a non-volatile memory and a data interface. The non-volatile memory has a capacity of ≥16GB and is used to record at least one year of temperature data and fault information. The data is not lost after power failure. The data interface is a USB-Type-C interface, which supports data export, threshold adjustment and firmware upgrade. It also supports the RS485 communication protocol for connecting to an industrial control system to achieve centralized monitoring.

[0014] Preferably, the outer shell is injection molded from PA66+glass fiber high temperature resistant and flame retardant engineering plastic, forming an integrated waterproof and sealed structure with a waterproof rating of IP65. The outer shell consists of an upper cover and a lower shell connected by bolts and sealed with a sealing ring. The bottom of the outer shell is provided with a magnetic fixing seat and M4 bolt fixing holes. The M4 bolt fixing holes are located on the outer perimeter of the magnetic fixing seat, adopting a dual fixing method of magnetic attraction and bolts to adapt to different installation scenarios.

[0015] Furthermore, the working process of this motor over-temperature self-recovery protector includes seven steps: initialization, normal operation, over-temperature warning, over-temperature protection, emergency over-temperature protection, self-recovery, and fault handling. It realizes automatic monitoring, protection, and self-recovery of motor over-temperature throughout the entire process, and also has fault self-checking and redundant backup functions to ensure protection reliability. The specific workflow is as follows: S1. Initialization: After the protector is connected to the motor circuit, the power supply module starts, the main power supply works first, and the backup power supply is in standby mode; after the control module completes self-test and confirms that each module is working normally, the temperature acquisition module starts to collect the real-time temperature of the motor windings and the housing and transmits it to the control module. S2. Normal operation: When the collected temperature is ≤ the warning threshold T1, the control module determines that the motor is operating normally, the execution module remains on, the motor works normally, the green light of the warning module is always on, and the data recording module continuously records temperature data. S3, Over-temperature warning: When the collected temperature is >T1 and ≤T2, the control module issues a warning command, the warning module flashes yellow light, the buzzer does not activate, the execution module remains on, the control module continuously monitors temperature changes, and the data recording module records the warning information. S4. Over-temperature protection: When the collected temperature is greater than T2 and less than or equal to T3, the control module issues a cut-off command, the drive circuit drives the relay to disconnect, and the self-resetting fuse is in a high-resistance state, thus doubly cutting off the main circuit of the motor and stopping the motor. The warning module flashes a red light and the buzzer sounds an alarm. The data recording module records the occurrence time of the over-temperature protection, the peak temperature, and other information. S5 Emergency Over-Temperature Protection: When the collected temperature > T3, the control module issues an emergency cut-off command, cutting off the motor main circuit and control circuit, and the motor stops running; the warning module's red light stays on, and the buzzer continuously sounds an alarm; the data recording module records the emergency over-temperature information. S6. Self-recovery: After the motor stops running, the temperature gradually decreases. When the collected temperature drops below T1, the control module detects that the temperature has returned to normal and there is no module fault. It issues a conduction command, the drive circuit drives the relay to close, the self-resetting fuse returns to a low-resistance state, the motor main circuit is turned on, and the motor automatically resumes operation; the warning module returns the green light to a constant state, and the buzzer stops alarming. S7. Fault Handling: If the control module detects a fault in a module (such as a temperature acquisition module fault or a relay fault), it will immediately issue a fault alarm command, the warning module's red light will flash, the buzzer will sound an alarm, and the fault type will be recorded at the same time; if the built-in acquisition unit fails, it will automatically switch to the external acquisition unit to ensure that the protection function is not interrupted; if the fault cannot be eliminated by itself, the protector will remain in the cut-off state until the fault is eliminated, at which point it will be manually restarted to restore normal operation.

[0016] Therefore, the present invention employs the above-mentioned motor over-temperature self-resetting protector, and the technical effects are as follows: Addressing the core pain points of existing protectors such as "inaccurate temperature acquisition, fixed protection thresholds, and poor self-recovery reliability," this invention creatively integrates functions such as dual temperature acquisition, three-level protection, adjustable thresholds, dual power supply backup, and fault self-testing into one, forming a collaborative working mechanism. This enables intelligent and precise motor over-temperature protection throughout the entire process, significantly improving protection effectiveness and reliability. Breaking through the limitations of existing self-resetting protectors that "can only perform a single protection action", this invention creatively incorporates an early warning module and a data recording module to achieve closed-loop management of "early warning-protection-self-resetting-fault tracing". This not only protects the motor from high-temperature damage, but also provides data support for the operation and maintenance of the motor, reducing maintenance costs. The innovative design incorporates magnetic and bolt-fixed dual-fixation and a waterproof sealed shell, along with an adjustable threshold function, enabling the protector to adapt to different types of motors and installation scenarios. This solves the technical problem of existing protectors having weak adaptability and being unsuitable for harsh environments.

[0017] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of an embodiment of a motor over-temperature self-resetting protector according to the present invention; Figure 2 This is a schematic diagram of the module connections of an embodiment of a motor over-temperature self-resetting protector according to the present invention; Figure 3 This is a flowchart illustrating the operation of an embodiment of a motor over-temperature self-recovery protector according to the present invention.

[0019] Figure Labels 1. Top cover; 2. Bottom shell; 3. Magnetic mounting base; 4. Three-color LED indicator; 5. Buzzer. Detailed Implementation

[0020] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.

[0021] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0022] Example 1 like Figure 1 , Figure 2 As shown, this embodiment provides a motor over-temperature self-recovery protector, suitable for a 1.5kW industrial servo motor. The specific parameters are set as follows: warning threshold T1=70℃, protection threshold T2=90℃, emergency protection threshold T3=120℃, anti-shake time=2s, sampling frequency=1 time / minute, backup power supply duration=36h, storage capacity=32GB.

[0023] The outer shell is made of PA66+ glass fiber high temperature resistant and flame retardant material. It is an integrated waterproof and sealed structure, divided into an upper cover 1 and a lower shell 2. It is connected by M3 bolts and has a waterproof rating of IP65. The bottom is equipped with a magnetic fixing seat 3. The magnetic fixing seat 3 has M4 bolt fixing holes on all four sides. The top of the upper cover 1 is equipped with a three-color LED indicator 4, and the front is equipped with a buzzer 5 (integrated mute button).

[0024] The lower left side of the lower shell 2 has an 8-pin terminal block, and the middle has a USB-Type-C data interface. Below the USB-Type-C data interface is a hidden threshold adjustment button. The terminal block uses high-temperature resistant copper terminals and is compatible with AC 220V power supply.

[0025] The built-in acquisition unit in the temperature acquisition module uses a surface-mount PT100 platinum resistance thermometer, which extends into the motor winding coil through a high-temperature resistant polytetrafluoroethylene wire and fits tightly with the winding. The wire passes through a pre-drilled hole in the side wall of the housing, and the hole is sealed with a high-temperature resistant sealing sleeve. The external acquisition unit uses an NTC thermistor, which fits into the motor housing.

[0026] Signal filtering unit: It adopts an RC filter circuit, which is integrated on the control module PCB board to filter electromagnetic interference signals (frequency 50Hz~1MHz) during the temperature acquisition process and improve the stability of the acquired signal. Switching logic: When the built-in acquisition unit is working normally, the external acquisition unit is in standby mode; when the control module detects an abnormal signal from the built-in acquisition unit (such as open circuit or short circuit), it automatically switches to the external acquisition unit within 0.5 seconds to ensure uninterrupted temperature acquisition.

[0027] The core chip in the control module is an STM32F103C8T6 microcontroller (ARM Cortex-M3 core, 72MHz clock speed, 64KB Flash capacity, 20KB RAM capacity), which is surface-mounted on the PCB board. A / D conversion unit: It adopts a built-in 12-bit A / D converter with adjustable sampling frequency and conversion accuracy of ±1LSB, which converts the analog voltage signal (0~3.3V) output by the temperature acquisition module into a digital signal; Logic judgment unit: Preset three temperature thresholds, combined with the rated operating temperature of the motor, set as follows: warning threshold T1=70℃, protection threshold T2=90℃, emergency protection threshold T3=120℃ (T1<T2<T3), compare the collected winding temperature and housing temperature with the preset thresholds in real time, and generate corresponding control commands; Threshold adjustment unit: Threshold adjustment is achieved through a hidden multi-turn potentiometer (model: 3296W-1-103, adjustment accuracy 1%), with adjustment ranges of T1 40℃~80℃, T2 80℃~120℃, and T3 120℃~150℃. Parameters are automatically saved after adjustment and are not lost upon power failure. It also supports connection to a host computer via USB-Type-C interface for threshold adjustment using dedicated software. Fault self-test unit: Real-time detection of the working status of temperature acquisition module, execution module, power supply module, early warning module and data recording module, with a detection frequency of 1 time / 10s. When a module fault is detected (such as sensor open circuit, relay fault, power interruption), the fault type and fault occurrence time are recorded immediately. Anti-shake unit: The anti-shake time is set to 2s (adjustable range 1~5s). When the temperature fluctuation is ≤2℃ / s, it is judged as a temperature fluctuation and the execution module is not triggered to avoid false protection due to temperature fluctuations during normal motor operation.

[0028] The self-resetting fuse (PPTC) in the execution module: Model: JK60-10, rated voltage 250V, rated current 10A, operating temperature 70℃, recovery temperature 50℃, is connected in series in the main circuit of the motor. When the temperature reaches T2 (90℃), the resistance rises rapidly to a high resistance state (≥100kΩ), limiting the main circuit current to ≤10mA; when the temperature drops below T1 (70℃), it automatically recovers to a low resistance state (≤0.1Ω). High-temperature resistant DC relay: Model: G5LE-14-DC12, rated voltage DC 12V, rated current 10A, contact life ≥100,000 times, temperature resistance 105℃, connected in series with a self-resetting fuse in the main circuit of the motor, controlled by the control module, response time ≤50ms; MOSFET driver circuit: The IRF540 MOSFET driver chip is used, with an input voltage of 5V and an output current of 2A. It connects the control module and the relay to amplify the control signal (3.3V) of the control module, ensuring the fast and stable operation of the relay, and also has overcurrent protection function. Connection: One end of the resettable fuse is connected to the input terminal of the motor main circuit, and the other end is connected to the normally closed contact of the high-temperature resistant DC relay. The other end of the high-temperature resistant DC relay is connected to the output terminal of the motor main circuit. The input terminal of the drive circuit is connected to the GPIO pin of the control module, and the output terminal is connected to the coil of the high-temperature resistant DC relay.

[0029] The main power supply in the power module is an AC / DC power module (model: AC-DC-05-10, input voltage AC 220V±10%, output voltage DC 5V and DC 12V, output current 2A, conversion efficiency ≥85%), which is fixed inside the upper front of the casing. The input terminals are connected to the power supply of the motor control circuit, and the output terminals supply power to each module. Backup power supply: Built-in 1500mAh rechargeable lithium battery (model: 18650, rated voltage 3.7V, cycle life ≥1000 times), connected to the main power supply module through the lithium battery management module (model: TP4056) to realize charging and discharging management; when the main power supply is normal, the lithium battery is in the charging state; when the main power supply is interrupted, it automatically switches to lithium battery power supply within 0.1s, and the backup power supply duration is ≥36h; Protection functions: The power module integrates overvoltage protection (DC 5.5V), overcurrent protection (2.5A), and short circuit protection to prevent damage to each module due to abnormal voltage or current.

[0030] The warning module includes a tri-color LED indicator 4: three working states corresponding to different colors and states. Normal operation: Green constant light (brightness 500 cd / m²) 2 ); Over-temperature warning: Yellow flashing (flashing frequency 1 time / second, duty cycle 50%); Over-temperature, emergency over-temperature, module failure: red flashing (flashing frequency 2 times / second) or red solid light (in case of emergency over-temperature); Buzzer 5: Model: SFM-27, rated voltage 5V, volume 85dB (at a distance of 1m), fixed on the right side of the top cover 1, with the sound outlet corresponding to the pre-drilled sound hole on the top cover 1, and only emits sound in the following scenarios: Over-temperature protection (T2 < temperature ≤ T3): intermittent alarm (1 second sound, 1 second silence); Emergency over-temperature protection (temperature > T3): Continuous alarm; Module fault: Intermittent alarm (0.5s on, 0.5s off); Mute button: Model TS-101, round, 5mm in diameter, integrated on the side surface of buzzer 5, with a pressing travel of 1mm. After pressing, buzzer 5 stops sounding. Pressing it again restores the alarm function. It resets after power failure.

[0031] Data recording module Non-volatile memory: Model: W25Q256JVFIQ, capacity 32GB, surface mount type, mounted on the upper rear of the PCB board, can record at least 1 year of temperature data and fault information, sampling frequency 1 time / minute, data is not lost after power failure; Data interface: USB-Type-C interface, running through the right side wall of the lower shell 2, supports data export (export format is Excel), threshold adjustment, and firmware upgrade; Communication function: Supports RS485 communication protocol (using MAX485 chip, communication rate 9600bps, communication distance ≤1000m), can be connected to industrial control system, realize centralized monitoring of multiple motor protectors, and upload temperature data and fault information in real time.

[0032] The PCB integrated board uses FR-4 fiberglass board (1.6mm thick, 70mm×50mm in size) with tin plating. Each module component is mounted by surface mounting or plug-in type. The wires are made of high-temperature resistant tin-plated copper wire (0.5~1mm in diameter) and are firmly soldered. The PCB board is fixed in the middle layer of the lower shell 2 cavity and is isolated from the outer shell by insulating gaskets to avoid short circuits.

[0033] The work process is as follows Figure 3 As shown: S1. Initialization (3s) The protector is connected to the motor circuit and the main power supply (AC 220V) is turned on. The power module starts up, and the main power supply works first to supply power to each module. The backup lithium battery is in a charging state. The control module starts up and completes self-test of the temperature acquisition module, execution module, early warning module and data recording module. After confirming that there are no faults in each module, it sends a start command. The temperature acquisition module starts to collect the real-time temperature of the motor winding and the housing at a frequency of 1 time / minute and transmits the analog temperature signal to the control module.

[0034] S2, Normal Operation After the motor starts, the winding temperature stabilizes at around 65℃ and the casing temperature stabilizes at around 58℃ during normal operation, both ≤ the warning threshold T1 (70℃). The control module converts the temperature signal into a digital signal through the A / D conversion unit. The logic judgment unit determines that the motor is operating normally, generates a conduction command, and the execution module maintains the conduction state, so the motor continues to operate normally. The three-color LED indicator 4 of the warning module is always on green, and the buzzer 5 does not activate. The data recording module continuously records the winding temperature and casing temperature data, recording one set every minute and storing it in non-volatile memory.

[0035] S3, Over-temperature warning When the motor experiences overload or stall, causing an increase in load and a gradual rise in winding temperature, when the winding temperature reaches 75℃ (>T1=70℃) and the casing temperature reaches 68℃ (≤T2=90℃), the control module's logic judgment unit determines an over-temperature warning state and generates a warning command. The warning module's three-color LED indicator 4 flashes yellow (1 flash per second), and the buzzer 5 remains silent. The execution module remains on, and the motor continues to run. The control module continuously monitors temperature changes, and the data recording module records the warning start time and real-time temperature data.

[0036] S4, Over-temperature protection If the motor is overloaded or stalled, and the winding temperature continues to rise, when the winding temperature reaches 95℃ (>T2=90℃) and the casing temperature reaches 82℃ (<T3=120℃), the control module's logic judgment unit determines it to be an over-temperature condition and immediately generates a cut-off command. After receiving the command, the drive circuit drives the high-temperature resistant DC relay to disconnect, and at the same time, the self-resetting fuse (PPTC) becomes high-resistance due to the temperature rise, thus doubly cutting off the motor's main circuit and stopping the motor. The warning module's three-color LED indicator 4 flashes red (flashing frequency 2 times / second), and the buzzer 5 intermittently alarms (sounding for 1 second, stopping for 1 second). The data recording module records the over-temperature protection occurrence time, temperature peak (winding 95℃, casing 82℃), protection duration, and other information.

[0037] S5, Emergency Over-Temperature Protection If the motor experiences a serious fault (such as a winding short circuit), the winding temperature will rise sharply. When the winding temperature reaches 125℃ (>T3=120℃) and the casing temperature reaches 90℃, the control module's logic judgment unit will determine that it is in an emergency over-temperature state and generate an emergency cut-off command. The execution module will cut off the motor's main circuit and control circuit, and the motor will stop running completely to prevent it from burning out. The warning module's three-color LED indicator 4 will remain constantly lit, and the buzzer 5 will continuously sound an alarm. The data recording module will record information such as the time of the emergency over-temperature occurrence, the peak temperature, and the fault type (emergency over-temperature).

[0038] S6, Self-recovery After the motor stops running, the internal temperature gradually decreases. When the winding temperature drops to 68℃ (<T1=70℃) and the casing temperature drops to 60℃, the control module detects that the temperature has returned to normal. At the same time, the fault self-test unit confirms that there are no faults in each module and generates a conduction command. The drive circuit drives the relay to close, the self-resetting fuse returns to the low resistance state, the main circuit of the motor is turned on, and the motor automatically resumes normal operation. The three-color LED indicator 4 of the warning module returns to a solid green light, and the buzzer 5 stops alarming. The data recording module records the self-recovery time and the temperature data at the time of recovery.

[0039] S7, Troubleshooting If the self-test unit detects a fault in a module, it immediately executes the fault handling procedure: Scenario 1: If the built-in PT100 sensor fails (open circuit or short circuit), the control module will automatically switch to the external NTC sensor within 0.5 seconds. At the same time, the red light on the warning module will flash, the buzzer will sound an intermittent alarm, and the data recording module will record the fault type (built-in sensor failure) and the time of the fault. At this time, the protector can still perform temperature monitoring and over-temperature protection normally without affecting the motor operation. Scenario 2: Relay failure (cannot disconnect). After the control module detects the fault, it immediately controls the self-resetting fuse to remain in a high-resistance state, cutting off the motor main circuit. At the same time, the warning module's red light flashes, buzzer 5 continuously alarms, and the data recording module records the fault type (relay failure). At this time, the motor stops running and requires manual troubleshooting. After replacing the relay, the protector is manually restarted to restore normal operation. Scenario 3: When the main power supply is interrupted, the power module automatically switches to the backup lithium battery power supply. The protector continues to perform temperature monitoring, fault recording, and early warning functions. The backup power supply lasts for 36 hours. After the main power supply is restored, it automatically switches to the main power supply and charges the lithium battery at the same time. After all faults are eliminated, manually restart the protector. The control module will complete its self-test and return to normal working mode.

[0040] Performance testing and verification To verify the performance of the protector in this embodiment, the following tests were conducted, and the test results all met the design requirements, as detailed below: 1. Temperature measurement accuracy test Test environment: Temperature 25℃, humidity 50%. The built-in PT100 sensor, external NTC sensor, and standard thermometer (accuracy ±0.1℃) were placed in the same constant temperature chamber. The temperature of the constant temperature chamber was adjusted to 40℃, 70℃, 90℃, and 120℃, and the difference between the sensor-collected temperature and the standard temperature was measured respectively. The test results are as follows: At 40℃: PT100 temperature acquisition temperature is 39.8℃, with an error of -0.2℃; NTC temperature acquisition temperature is 40.5℃, with an error of +0.5℃; At 70℃: PT100 temperature reading is 70.2℃, with an error of +0.2℃; NTC temperature reading is 70.8℃, with an error of +0.8℃. At 90℃: PT100 temperature reading is 89.7℃, with an error of -0.3℃; NTC temperature reading is 90.9℃, with an error of +0.9℃. At 120℃: PT100 temperature acquisition is 120.3℃, with an error of +0.3℃; NTC temperature acquisition is 121.0℃, with an error of +1.0℃; Conclusion: The temperature measurement accuracy meets the design requirements (PT100±0.5℃, NTC±1℃).

[0041] 2. Response speed test Test method: The PT100 sensor was rapidly heated with a hot air gun until the temperature rose from 70℃ to 90℃ (over-temperature protection threshold). The time from when the control module issued a cut-off command to when the execution module cut off the circuit was measured using an oscilloscope. The test was repeated 10 times. The test results are as follows: Response time range: 35~48ms, average response time 42ms, ≤50ms, meets design requirements.

[0042] 3. Self-recovery reliability test Test method: Simulate over-temperature protection-self-recovery cycle, repeat the test 1000 times, record the number of successful self-recoverys, and the test results are as follows: The self-recovery function succeeded 999 times and failed once (due to a temporary power outage of the lithium battery), with a self-recovery reliability of 99.9%, which meets the design requirements.

[0043] 4. Environmental adaptability test Waterproof and dustproof test: Place the protector in an IP65 waterproof and dustproof test chamber and test for 24 hours. After taking it out, check that each module is working normally, no dust or moisture enters, and the wiring terminals are free from oxidation. Vibration test: Fix the protector to the vibration test bench, set the vibration frequency to 10~50Hz, amplitude to 0.5mm, and test for 24 hours. If there is no loosening of any module, the device is working normally. High and low temperature test: The protector was placed in a high and low temperature test chamber and operated for 24 hours at -10℃ and 60℃ respectively. All modules worked normally, and there were no abnormalities in temperature acquisition, early warning and protection functions.

[0044] 5. Service life test Test method: Simulating normal motor operation, the protector was continuously operated for 10,000 hours, and the performance of each module was tested. The results are as follows: The casing shows no deformation or aging, the sensor's acquisition accuracy shows no decline, the relay contacts show no wear, the lithium battery capacity decays by ≤10%, the data recording module stores data normally, and the design requirement of a service life of ≥5 years is met.

[0045] Therefore, the present invention adopts the above-mentioned motor over-temperature self-recovery protector to achieve accurate monitoring of motor winding temperature, and at the same time has over-temperature warning, fault recording and feedback functions, which improves the safety and reliability of motor operation, reduces maintenance costs, and adapts to the usage needs of different types and power motors.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A motor over-temperature self-resetting protector, characterized in that: It includes a housing, a temperature acquisition module, a control module, an execution module, a power supply module, an early warning module, and a data recording module. All modules are integrated inside the housing, and the housing is fixedly connected to the motor housing. The temperature acquisition module is used to acquire the real-time temperature of the motor windings and housing, and output a temperature signal; the control module receives the temperature signal and outputs control commands according to a preset temperature threshold; the execution module receives the control commands and realizes the disconnection and self-recovery of the motor circuit; the power supply module supplies power to each module; the early warning module receives the control commands and issues graded early warning signals; the data recording module records temperature data and fault information.

2. The motor over-temperature self-resetting protector according to claim 1, characterized in that: The temperature acquisition module includes a built-in PT100 platinum resistance acquisition unit, an external NTC thermistor acquisition unit, and a signal filtering unit; the built-in unit extends into the winding, and the external unit is attached to the motor housing. When the built-in unit fails, it automatically switches to the external unit.

3. The motor over-temperature self-resetting protector according to claim 1, characterized in that: The control module uses an STM32 series microcontroller, which integrates an A / D conversion unit, a logic judgment unit, a threshold adjustment unit, a fault self-test unit, and an anti-shake unit. The A / D conversion unit converts the analog temperature signal output by the temperature acquisition module into a digital signal; the logic judgment unit presets a warning threshold T1, a protection threshold T2, and an emergency protection threshold T3, where T1 < T2 < T3; the threshold adjustment unit flexibly adjusts the values ​​of T1, T2, and T3 via a hidden adjustment knob or a host computer interface; the fault self-test unit monitors the working status of each module in real time and records the fault type; the anti-shake unit adjusts the anti-shake time, ranging from 1 to 5 seconds.

4. The motor over-temperature self-resetting protector according to claim 1, characterized in that: The execution module includes a self-resetting fuse PPTC, a high-temperature resistant DC relay, and a MOSFET drive circuit. The PPTC and the high-temperature resistant DC relay are connected in series in the main circuit of the motor to form a double cut-off. The MOSFET drive circuit connects the control module and the high-temperature resistant DC relay, with a response time of ≤50ms.

5. A motor over-temperature self-resetting protector according to claim 1, characterized in that: The power module adopts a dual power supply mode, including a main power supply and a backup power supply; the main power supply is an AC / DC power module that outputs DC 5V and DC 12V, which are used to power the control system and relays, respectively; the backup power supply is a built-in rechargeable lithium battery that automatically switches when the main power supply is interrupted, and the backup power supply has a battery life of not less than 24 hours.

6. The motor over-temperature self-resetting protector according to claim 1, characterized in that: The warning module includes a three-color LED indicator and a buzzer. The three-color LED indicator and the buzzer are both located on the top of the housing. The three-color LED indicator corresponds to three working states: green is solid for normal operation, yellow is flashing for over-temperature warning, and red is flashing or solid for over-temperature, emergency over-temperature, or fault status. The mute button is integrated into the side surface of the buzzer.

7. A motor over-temperature self-resetting protector according to claim 1, characterized in that: The data recording module includes a non-volatile memory and a data interface. The non-volatile memory has a capacity of ≥16GB. The data interface is a USB-Type-C interface, which supports data export, threshold adjustment and firmware upgrade. It also supports the RS485 communication protocol for connecting to an industrial control system to achieve centralized monitoring.

8. A motor over-temperature self-resetting protector according to claim 1, characterized in that: The outer shell is divided into an upper cover and a lower shell that are connected by bolts and sealed by a sealing ring. The outer shell has a waterproof rating of IP65. The bottom of the outer shell is provided with a magnetic fixing seat and M4 bolt fixing holes, which are located on the outer perimeter of the magnetic fixing seat.

Images