Intelligent LED driving power supply and lighting control method thereof

Abstract

This invention discloses an intelligent LED driver power supply and lighting control method. The driver power supply includes a main power circuit, an intelligent control module, a dimming module, a protection module, an NFC programming module, and a communication module. The intelligent control module selects the dimming mode according to DALI priority rules and smoothly adjusts the output current in gradients not exceeding 1% of the current value each time, solving the flickering problem during dimming switching. It activates gradient derating protection when there is external over-temperature, and selectively executes self-recovery or non-self-recovery protection based on the version identifier when there is internal over-temperature, forming a graded temperature protection mechanism. Protection events are stored as fault logs and read via the NFC module. This invention integrates dimming priority determination and smooth transition logic into the same control core, and associates graded temperature protection with fault log storage to form an integrated protection, recording, and diagnostic link, achieving flicker-free dimming, refined protection, and efficient operation and maintenance.

Description

Technical Field

[0001] This invention relates to the field of LED driver power supply technology, and in particular to an intelligent LED driver power supply and its lighting control method suitable for mid-to-high-end scenarios such as outdoor road lighting. Background Technology

[0002] LED lighting, with its advantages of high efficiency, energy saving, and long lifespan, has become the mainstream choice for outdoor lighting. As a core component of the lighting system, the performance of the LED driver directly determines the stability, intelligence, and energy efficiency of the entire system. With the evolution of smart lighting technology, especially the promotion of the Zhaga & DALI Alliance D4i standard, the market has placed higher demands on LED drivers: they must be compatible with mainstream smart control protocols (such as DALI-2 and D4i), support multi-mode fine-tuning, possess reliable protection mechanisms to adapt to harsh outdoor environments, and enable rapid local deployment and remote centralized management.

[0003] Existing LED driver power supplies and their control methods typically suffer from the following technical defects: 1. Inadequate dimming mechanism and poor user experience: Some products only support a single dimming mode, lacking flexibility. A few products supporting multiple dimming modes lack clear mode switching priority rules, and when switching between different dimming modes or changing dimming values, sudden current changes often cause noticeable flickering in the LED lights. 2. Simple protection mechanism and weak outdoor adaptability: Traditional over-temperature protection is mostly single-threshold triggering and on / off execution. This type of switch-type protection can cause the lights to periodically turn off or restart when outdoor ambient temperatures fluctuate frequently, seriously affecting the lighting experience and the lifespan of the lights. 3. Low debugging and networking efficiency and insufficient compatibility: Parameter configuration usually relies on external programmers or professional software, making on-site debugging cumbersome. Most products can only store a single configuration scheme, unable to quickly adapt to switching between different lighting scenarios. Regarding communication protocol support, some products are not fully compatible with mainstream standards such as D4i, resulting in limited networking capabilities with upper-level intelligent lighting control systems and poor compatibility. Summary of the Invention

[0004] To address the comprehensive technical problems existing in the prior art, such as flickering during dimming switching, crude protection mechanisms, low debugging efficiency, and poor compatibility, this application provides an intelligent LED driver power supply and lighting control method to achieve smooth adaptive switching of dimming, hierarchical refined protection, and efficient local / remote dual debugging, thereby improving the reliability, intelligence level, and outdoor adaptability of LED lighting systems.

[0005] To solve one of the aforementioned technical problems, the following technical solution is adopted: This application provides an intelligent LED driver power supply, including: The main power supply circuit converts AC input into a stable DC output suitable for LED loads. It includes a rectifier and filter unit, a DC-DC converter unit, and an output voltage regulator unit, adapting to a wide voltage input range and providing an adjustable constant current output.

[0006] The intelligent control module, as the core control unit of the drive power supply, has a built-in programmable control logic chip. This module is configured to perform the following functions: (a) According to the preset dimming mode priority rules, when multiple dimming signals exist at the same time, the DALI dimming signal is selected as the effective dimming command, wherein the priority rule is that the DALI dimming unit has a higher priority than the time-controlled dimming unit and the AC dimming unit. (b) When executing a dimming command, the output current is controlled to change gradually with an adjustment step of no more than 1% of the current value each time, so that the current change curve during the dimming mode switching process is continuous without abrupt changes. (c) When the ambient temperature is detected to reach the first threshold, the gradient output current derating protection is activated, so that the output current decreases linearly as the temperature rises; when the ambient temperature is detected to reach the second threshold higher than the first threshold, the output current is limited to a preset percentage of the rated current. (d) When the internal device temperature is detected to exceed the third threshold, the self-recovering over-temperature protection or the non-self-recovering over-temperature protection is selectively executed according to the preset version identifier of the drive power supply. Furthermore, the protection events triggered by the protection module are stored as fault logs, which can be read by external devices via the NFC programming module.

[0007] The dimming module includes a DALI dimming unit, a time-controlled dimming unit, and an AC dimming unit, which are connected to the intelligent control module to receive different types of external dimming commands.

[0008] The protection module, connected to the intelligent control module and the main power supply circuit, is used to monitor operating parameters and execute protection actions.

[0009] The NFC programming module communicates bidirectionally with the smart control module to store configuration parameters and fault logs, and supports offline touch programming.

[0010] The communication module connects to the intelligent control module and is compatible with DALI-2 and D4i protocols, used for data interaction with external intelligent lighting systems.

[0011] Based on the above-mentioned driving power supply, the present invention also provides a lighting control method, comprising the following steps: S1: Power-on initialization, read the pre-stored configuration parameters in the NFC programming module; S2: Real-time acquisition of multi-dimensional operating parameters, including electrical parameters, temperature parameters, and external dimming signals; S3: Based on the dimming mode priority rules and the acquired dimming signal, select the corresponding dimming mode, and gradually adjust the output current by adjusting the step size by no more than 1% of the current value each time. S4: Monitor operating parameters in real time and execute corresponding protection actions when protection conditions are triggered, including gradient output current derating protection and selective over-temperature protection; S5: Store the events triggered by the protection action as a fault log and upload the fault information in real time through the communication module; S6: Receives remote debugging commands via the communication module or on-site touch programming commands via the NFC programming module to update configuration parameters; S7: Repeat steps S2 to S6.

[0012] By adopting the above technical solution, compared with existing technologies, priority determination logic and smooth transition logic are integrated into the same control core, making them tightly coupled in terms of time dimension and control precision. Priority rules ensure the uniqueness of instruction sources and avoid multi-source conflicts; smooth transition logic ensures the continuity of the execution process and avoids current surges. The two work together to achieve truly flicker-free operation during dimming mode switching. Fault log writing and reading are achieved using the same NFC channel, forming an integrated link for protection, recording, and diagnosis. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the module structure of the intelligent LED driver power supply of the present invention; Figure 2 This is a schematic diagram illustrating the working logic and priority of the dimming module of the present invention; Figure 3 This is a schematic diagram of the working process and gradient derating curve of the graded temperature protection unit of the present invention; Figure 4 This is a schematic flowchart of the lighting control method of the present invention; Figure 5 This is a schematic diagram of the voltage difference verification logic of the AC dimming unit of the present invention; Figure 6 This is a schematic diagram comparing the current change curves during dimming switching of the present invention and existing technologies. Detailed Implementation

[0014] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments: An intelligent LED driver power supply, comprising: The main power supply circuit is used to provide regulated driving power to the LED load; The intelligent control module, connected to the main power circuit, is configured to perform dimming control and protection management. The dimming module includes a DALI dimming unit, a time-controlled dimming unit, and an AC dimming unit, which are respectively connected to the intelligent control module; The protection module is connected to the intelligent control module and the main power supply circuit, and is used to monitor operating parameters and perform protection actions; The NFC programming module communicates bidirectionally with the intelligent control module and is used to store configuration parameters and fault logs; It also includes a communication module, which is connected to the intelligent control module for data interaction with external systems.

[0015] The intelligent control module includes: (a) According to the preset dimming mode priority rule, when multiple dimming signals exist at the same time, the DALI dimming signal is selected as the effective dimming command, wherein the priority rule is that the priority of the DALI dimming unit is higher than that of the time-controlled dimming unit and the AC dimming unit. (b) When executing a dimming command, the output current of the main power supply circuit is controlled to change gradually with an adjustment step of no more than 1% of the current value each time, so that the current change curve during the dimming mode switching process is continuous without abrupt changes. (c) When the protection module detects that the external ambient temperature reaches the first threshold, it activates the gradient output current derating protection, so that the output current decreases linearly as the temperature rises; when the external ambient temperature is detected to reach the second threshold higher than the first threshold, the output current is limited to a preset percentage of the rated current. (d) When the protection module detects that the internal device temperature exceeds the third threshold, it selectively executes self-recovering over-temperature protection or non-self-recovering over-temperature protection according to the preset version identifier of the drive power supply; and the intelligent control module also stores the protection events triggered by the protection module as a fault log, which can be read by external devices through the NFC programming module.

[0016] The time-controlled dimming unit supports an adaptive center point alignment mode. The intelligent control module only allows the adaptive center point alignment mode to be executed when it determines that the power-on working time for at least two days in the past two days has exceeded 2 hours and the difference between the power-on working time for at least two days does not exceed 15 minutes.

[0017] The intelligent control module also has a built-in voltage difference verification logic, which is used to verify the configuration parameters of the AC dimming unit. The voltage difference verification logic is configured to determine that the parameters are invalid and lock the AC dimming function when the voltage difference between the starting input voltage and the cutting-off input voltage is less than 20Vac, or the voltage difference between the current input voltage and the starting input voltage is less than 5Vac.

[0018] In the graded temperature protection unit, the sensor used to detect the external ambient temperature is a negative temperature coefficient thermistor with parameters R25=10K and B value range of 3350-3399. The gradient output current derating protection is as follows: when the resistance of the thermistor drops to 1.67KΩ, the output current begins to decrease; when the resistance of the thermistor drops to 1.27KΩ, the output current is reduced to 25% of the rated current.

[0019] In addition, the communication module is compatible with the DALI-2 and D4i protocols and supports uploading fault information triggered by the protection module to an external system in real time. The fault log is stored in the NFC programming module.

[0020] The power supply's main circuit has a rated input voltage of 200-277Vac, an adjustable output current range of 500-1050mA, an output ripple current flicker coefficient of no more than 5%, a constant current accuracy of ±3%, and a standby power consumption of no more than 0.5W. The power supply's components are compatible with both CLASS I and CLASS II luminaires, and differentiated potting processes are used for different lifespan ratings: for an 80,000-hour lifespan rating, a semi-potting silicone coating followed by conformal coating is used.

[0021] This application also provides a lighting control method for an intelligent LED driver power supply, comprising the following steps: S1: Power-on initialization, read the pre-stored configuration parameters in the NFC programming module; S2: Real-time acquisition of multi-dimensional operating parameters, including electrical parameters, temperature parameters, and external dimming signals; S3: Based on the dimming mode priority rules and the acquired dimming signal, select one of DALI dimming, time-controlled dimming, or AC dimming as the current dimming mode, and during the dimming process, gradually adjust the output current by adjusting the step size by no more than 1% of the current value each time. S4: Real-time monitoring of operating parameters. When protection conditions are triggered, corresponding protection actions are executed, including: when the external ambient temperature reaches the first threshold, gradient output current derating protection is activated; when the internal device temperature exceeds the third threshold, self-resetting or non-self-resetting over-temperature protection is selectively executed according to the preset version identifier. S5: Store the events triggered by the protection action as a fault log and upload the fault information in real time through the communication module; S6: Receive remote debugging instructions via the communication module or on-site touch programming instructions via the NFC programming module to update the configuration parameters; S7: Repeat steps S2 to S6.

[0022] In step S3, when the AC dimming mode is selected, the voltage difference between the starting input voltage and the cutting-off input voltage is checked in real time to see if it is less than 20Vac, and the voltage difference between the current input voltage and the starting input voltage is less than 5Vac. If either check fails, the AC dimming function is locked and a parameter abnormality prompt is issued. In step S4, the gradient output current derating protection is specifically implemented as follows: a negative temperature coefficient thermistor with R25=10K and a B value range of 3350-3399 is used to detect the external ambient temperature. When the resistance of the thermistor drops to 1.67KΩ, the output current is reduced. When the resistance drops to 1.27KΩ, the output current is reduced to 25% of the rated current.

[0023] Example 1: Hardware Implementation of an Intelligent LED Driver Power Supply This embodiment provides a specific intelligent LED driver power supply, the structure of which is as follows: Figure 1 As shown.

[0024] The main power supply circuit 1 consists of a rectifier and filter unit 11 composed of EMI filtering and bridge rectification, a DC-DC converter unit 12 using LLC resonant topology, and a constant current controlled output voltage regulator unit 13. The rated input voltage is 200-277Vac, the output current is adjustable within the range of 500-1050mA, covering a power range of 22W to 200W, the output ripple flicker coefficient is ≤3%, the constant current accuracy is ±2%, and the standby power consumption is ≤0.4W.

[0025] Intelligent Control Module 2: Employs an STM32 series MCU with pre-installed control program. This program includes: Dimming mode priority rules: The DALI dimming unit has a higher priority than the time-controlled dimming unit and the AC dimming unit, ensuring that the system behavior is predictable when there are multiple signal sources.

[0026] Smooth transition logic: The execution of any dimming command adjusts the output current through the PWM signal in a gradient step of no more than 1% of the current value.

[0027] Voltage difference verification logic: Before executing AC dimming, verify whether the voltage difference between the start voltage and the cutoff voltage is ≥20Vac, and whether the voltage difference between the current voltage and the start voltage is ≥5Vac. If the verification fails, lock the AC dimming and issue an alarm.

[0028] Hierarchical temperature protection logic: integrates selective execution of internal over-temperature protection and gradient derating control for external over-temperature.

[0029] NFC Programming Module 3: Employs a 13.56MHz band chip and connects to the MCU via an I2C interface. Its internal storage is divided into five areas to store five complete configuration schemes, and a dedicated area for storing fault logs. On-site debugging personnel can retrieve and write schemes or read fault logs simply by touching the NFC reader / writer.

[0030] Dimming Module 4: DALI Dimming Unit 43: Physical layer compatible with DALI-2 protocol, receiving digital dimming signals from the bus.

[0031] Time-controlled dimming unit 41: Built-in RTC, supports adaptive center point alignment mode. The MCU checks the work logs of the past two days at midnight every day. Only when the power-on time of both days is greater than 2 hours and the difference between the two is ≤15 minutes, will it allow automatic adjustment of the dimming curve to align the center point with local midnight.

[0032] AC dimming unit 42: Determines dimming commands by detecting the conduction angle of the input voltage. Its configuration parameters are set via the NFC module, and the MCU executes voltage difference verification logic before execution.

[0033] Protection Module 5: Graded Temperature Protection Unit 51: Internal over-temperature: Detected by an onboard temperature sensor. In the standard version, output automatically resumes after the temperature drops following triggering; in the TEDAS version, output is locked upon triggering and requires manual power-off reset.

[0034] External over-temperature: Detected by an external NTC thermistor. The MCU reads its resistance value in real time. When the resistance drops to 1.67KΩ, corresponding to approximately 55℃, the output current begins to decrease linearly; when the resistance drops to 1.27KΩ, corresponding to approximately 65℃, the output current drops to 25% of the rated value.

[0035] Input / output voltage protection unit 52 and current protection unit 53: Equipped with input undervoltage protection (150Vac), input overvoltage protection (320Vac), output overvoltage, output overload, and short circuit protection. Upon triggering, protection employs either hiccup or clamping mechanisms, and automatically recovers after the fault is removed. The main power supply circuit can withstand 350Vac input for up to 8 hours.

[0036] Lightning protection unit 54: It adopts a combination of varistor and gas discharge tube to meet the 6-10KV lightning protection level.

[0037] Communication Module 6: Employs an isolated DALI transceiver, supporting DALI-2 and D4i protocols, enabling bidirectional communication with the upper-level control system, reporting fault information, and receiving remote commands.

[0038] Structure and Manufacturing Process: The housing adopts an upper cover and lower plastic shell structure, with an IP20 protection rating, compatible with CLASS I and CLASS II luminaires. For the 80,000-hour lifespan model, a half-filled silicone sealant + impregnation with conformal coating process is used; for the 100,000-hour lifespan model, a full-filled silicone sealant process is used, and the housing is modified to avoid glue overflow.

[0039] Example 2: A lighting control method based on the driving power supply This embodiment applies the driving power supply described in Embodiment 1 to a municipal street lighting system, referencing... Figure 4 The control method is as follows: S1: Power-on initialization When the municipal streetlights are powered on, the drive power supply starts. The intelligent control module 2 performs a self-test, confirming that the main power circuit 1, dimming module 4, protection module 5, and communication module 6 are working properly. Then, it reads the pre-stored configuration parameters from the NFC programming module 3: the adaptive center-point alignment mode of time-controlled dimming is enabled, DALI is the backup mode, AC is the fallback mode, and the protection threshold is set according to the municipal outdoor lighting standard.

[0040] S2: Real-time acquisition of operating parameters The intelligent control module 2 collects data in real time from various sensors, including: input voltage, input current, output voltage, output current, internal temperature, external NTC resistance reflecting the external ambient temperature, and DALI bus signals.

[0041] S3: Dimming Mode Determination and Smoothing Adjustment The system did not receive a DALI signal and determined that it had entered time control mode. The MCU retrieved the power-on durations of the past two days, which were both 10.2 hours and 10.1 hours, respectively. These met the preset conditions of >2 hours and a difference ≤15 minutes, therefore, it executed the adaptive center-point alignment mode, automatically aligning the midpoint of the dimming curve to the local midnight. During dimming, for each change in dimming step size, the MCU controlled the output current to change smoothly with a 1% gradient. Figure 6 As shown, compared with the current change curve of the prior art, the current change curve of the present invention is smooth and continuous, realizing flicker-free dimming.

[0042] S4: Hierarchical real-time protection and fault reporting On a summer afternoon, the ambient temperature outside the streetlights rose sharply, causing the external NTC resistance to drop to approximately 1.67KΩ (around 55°C). The MCU detected this change and immediately activated the gradient-type external over-temperature protection, linearly reducing the output current. When the resistance dropped to approximately 1.27KΩ (around 65°C), the output current decreased to 25% of the rated value, effectively protecting the light fixture. Simultaneously, the communication module 6 reported the current temperature value to the municipal lighting management platform in real time and stored the event as a fault log in the local NFC module.

[0043] S5: Local / Remote Dual Debugging Maintenance personnel issue instructions through the municipal lighting management platform, requesting that the street light brightness be adjusted to 80%. After receiving the instructions, the communication module 6 adjusts the output current in a gradient of 1% per cycle to complete the remote dimming.

[0044] On-site maintenance personnel used an NFC handheld terminal to touch the street light driver power supply, writing another pre-stored configuration scheme within one minute, completing rapid on-site debugging. During the debugging process, the NFC module supports one-click retrieval of multiple pre-stored schemes, eliminating the need for external specialized equipment.

[0045] S6: Execute in a loop The driving power supply continues to work, and the intelligent control module executes steps S2 to S5 in a loop to achieve dynamic adjustment of lighting parameters and real-time protection of the power supply.

[0046] Example 3: Parameter Verification and Anomaly Handling of AC Dimming like Figure 5 As shown, a field maintenance worker attempted to configure AC dimming parameters via an NFC programming module, setting the initial input voltage to 220Vac, the cutoff input voltage to 205Vac, and the voltage difference to 15Vac. The voltage difference verification logic of the intelligent control module detected that the voltage difference between the initial and cutoff voltages was 15Vac, which was less than 20Vac. It determined the parameters were invalid, immediately locked the AC dimming function, and sent an "AC dimming parameter abnormal" message to the management platform via the communication module. Simultaneously, it recorded the abnormal event in the fault log.

[0047] After the maintenance personnel read the fault log through the management platform or NFC, they reconfigure the parameters, setting the initial input voltage to 220Vac, the cutoff input voltage to 180Vac, and the voltage difference to 40Vac. The current input voltage is 230Vac, and the voltage difference between the initial voltage and the current input voltage is 10Vac. The verification passes, and the AC dimming function returns to normal.

Claims

1. An intelligent LED driver power supply, characterized in that, include: The main power supply circuit is used to provide regulated driving power to the LED load; The intelligent control module, connected to the main power circuit, is configured to perform dimming control and protection management. The dimming module includes a DALI dimming unit, a time-controlled dimming unit, and an AC dimming unit, which are respectively connected to the intelligent control module; The protection module is connected to the intelligent control module and the main power supply circuit, and is used to monitor operating parameters and perform protection actions; The NFC programming module communicates bidirectionally with the intelligent control module and is used to store configuration parameters and fault logs; It also includes a communication module, which is connected to the intelligent control module for data interaction with external systems.

2. The intelligent LED driver power supply according to claim 1, characterized in that, The intelligent control module: (a) According to the preset dimming mode priority rule, when multiple dimming signals exist at the same time, the DALI dimming signal is selected as the effective dimming command, wherein the priority rule is that the priority of the DALI dimming unit is higher than that of the time-controlled dimming unit and the AC dimming unit. (b) When executing a dimming command, the output current of the main power supply circuit is controlled to change gradually with an adjustment step of no more than 1% of the current value each time, so that the current change curve during the dimming mode switching process is continuous without abrupt changes. (c) When the protection module detects that the external ambient temperature reaches the first threshold, it activates the gradient output current derating protection, so that the output current decreases linearly as the temperature rises; when the external ambient temperature is detected to reach the second threshold higher than the first threshold, the output current is limited to a preset percentage of the rated current. (d) When the protection module detects that the internal device temperature exceeds the third threshold, it selectively executes self-recovering over-temperature protection or non-self-recovering over-temperature protection according to the preset version identifier of the drive power supply; and the intelligent control module also stores the protection events triggered by the protection module as a fault log, which can be read by external devices through the NFC programming module.

3. The intelligent LED driver power supply according to claim 1 or 2, characterized in that, The time-controlled dimming unit supports an adaptive center point alignment mode; the intelligent control module only allows the adaptive center point alignment mode to be executed when it determines that the power-on working time for at least two days in the past two days has exceeded 2 hours and the difference between the power-on working time for at least two days does not exceed 15 minutes.

4. The intelligent LED driver power supply according to claim 1 or 2, characterized in that, The intelligent control module also has a built-in voltage difference verification logic, which is used to verify the configuration parameters of the AC dimming unit. The voltage difference verification logic is configured to determine that the parameters are invalid and lock the AC dimming function when the voltage difference between the starting input voltage and the cutting-off input voltage is less than 20Vac, or the voltage difference between the current input voltage and the starting input voltage is less than 5Vac.

5. The intelligent LED driver power supply according to claim 1 or 2, characterized in that, In the graded temperature protection unit, the sensor used to detect the external ambient temperature is a negative temperature coefficient thermistor with parameters R25=10K and B value range of 3350-3399. The gradient output current derating protection is as follows: when the resistance of the thermistor drops to 1.67KΩ, the output current begins to decrease; when the resistance of the thermistor drops to 1.27KΩ, the output current is reduced to 25% of the rated current.

6. The intelligent LED driver power supply according to claim 1 or 2, characterized in that, The communication module is compatible with the DALI-2 and D4i protocols and supports uploading fault information triggered by the protection module to an external system in real time. The fault log is stored in the NFC programming module.

7. The intelligent LED driver power supply according to claim 1 or 2, characterized in that, The rated input voltage of the main power supply circuit is 200-277Vac, the adjustable output current range is 500-1050mA, the flicker coefficient of the output ripple current is no greater than 5%, the constant current accuracy is ±3%, and the standby power consumption is no greater than 0.5W.

8. A lighting control method based on the intelligent LED driver power supply according to any one of claims 1-7, characterized in that, Includes the following steps: S1: Power-on initialization, read the pre-stored configuration parameters in the NFC programming module; S2: Real-time acquisition of multi-dimensional operating parameters, including electrical parameters, temperature parameters, and external dimming signals; S3: Based on the dimming mode priority rules and the acquired dimming signal, select one of DALI dimming, time-controlled dimming, or AC dimming as the current dimming mode, and during the dimming process, gradually adjust the output current by adjusting the step size by no more than 1% of the current value each time. S4: Real-time monitoring of operating parameters. When protection conditions are triggered, corresponding protection actions are executed, including: when the external ambient temperature reaches the first threshold, gradient output current derating protection is activated; when the internal device temperature exceeds the third threshold, self-resetting or non-self-resetting over-temperature protection is selectively executed according to the preset version identifier. S5: Store the events triggered by the protection action as a fault log and upload the fault information in real time through the communication module; S6: Receive remote debugging instructions via the communication module or on-site touch programming instructions via the NFC programming module to update the configuration parameters; S7: Repeat steps S2 to S6.

9. The lighting control method according to claim 8, characterized in that, In step S3, when the AC dimming mode is selected, the voltage difference between the starting input voltage and the cutting-off input voltage is checked in real time to see if it is less than 20Vac, and the voltage difference between the current input voltage and the starting input voltage is less than 5Vac. If either check fails, the AC dimming function is locked and a parameter abnormality prompt is issued. In step S4, the gradient output current derating protection is specifically implemented as follows: a negative temperature coefficient thermistor with R25=10K and a B value range of 3350-3399 is used to detect the external ambient temperature. When the resistance of the thermistor drops to 1.67KΩ, the output current is reduced. When the resistance drops to 1.27KΩ, the output current is reduced to 25% of the rated current.

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