A street light dimming method and system

Abstract

The application provides a street lamp dimming method and system, and belongs to the technical field of lighting equipment control. The method comprises the following steps: initially setting a LED street lamp dimming voltage as 0V, dividing the 0V-10V dimming voltage into multiple continuous step values; controlling the dimming voltage to rise from 0V and drop from 10V to perform bidirectional scanning, recording the active power and power factor corresponding to each voltage after each adjustment, and waiting for the current, voltage and power factor to be stable; calculating the average value of the power and power factor of the same voltage, and storing the dimming voltage power data table to realize the accurate correspondence between the dimming voltage and the output power; after obtaining the target power, the target dimming voltage is obtained by table lookup, and a control signal is output to control the brightness; the actual power of the street lamp is collected in real time, and if the deviation between the actual power and the target power exceeds the preset range, the dimming voltage is adjusted to make the deviation return to the range, so that the brightness of multiple street lamps is consistent. The application can eliminate the problem of inconsistent brightness between different lamps.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lighting device control, in particular to a street lamp dimming method and system. BACKGROUND

[0002] With the large-scale application of LED lamps, it has significant advantages in energy saving, long life, etc. However, during use, the maximum active power, power factor and other performance indicators of LED lamps will decrease with the life decay.

[0003] Most of the existing dimming methods use open-loop control, only set the dimming voltage, and do not perform closed-loop feedback and dynamic adjustment on output current, voltage, power and other parameters. This method has the following defects:

[0004] (1) With the increase of use time, the brightness of the lamp gradually decreases;

[0005] (2) In the same section, due to different aging degrees of the lamps, the brightness is inconsistent;

[0006] (3) Due to the LED dimming characteristics, when the voltage rises from 0V or drops from the highest value to the target value, different powers may be generated at the same voltage, which aggravates the inconsistency. SUMMARY

[0007] Therefore, the present application provides a street lamp dimming method and system to eliminate the problem of inconsistent brightness between different lamps.

[0008] The technical solution adopted by the present application is:

[0009] In a first aspect, the present application provides a street lamp dimming method, comprising:

[0010] The dimming voltage of the LED street lamp is initially set to 0V, and the dimming voltage from 0V to 10V is divided into a plurality of continuous dimming voltage step values;

[0011] The dimming voltage is gradually scanned from 0V up and from 10V down, and after each adjustment, the current, voltage and power factor are stabilized, and the active power and power factor corresponding to each dimming voltage are recorded respectively;

[0012] For the same dimming voltage, the average active power P1 and the average power factor PF1 corresponding to the up and down scans are calculated;

[0013] The dimming voltage is associated with the average active power P1 and the average power factor PF1 and is stored to form a dimming voltage power data table;

[0014] Obtain the target power of the LED street light to be adjusted, find the target dimming voltage by reverse matching according to the dimming voltage power data table, and output a dimming control signal according to the target dimming voltage to control the brightness of the LED street light to be adjusted.

[0015] The actual power of the LED street light to be adjusted is collected in real time. If the deviation between the actual power and the target power exceeds the preset allowable range, the dimming voltage is adjusted to bring the deviation back to the preset allowable range and ensure consistent brightness.

[0016] Furthermore, the dimming voltage step value is divided as follows: the dimming voltage range of 0V to 10V is divided into 1000 parts, and each step value is 0.01V.

[0017] Furthermore, the control dimming voltage is gradually increased from 0V and gradually decreased from 10V. After each adjustment, once the current, voltage, and power factor stabilize, the active power and power factor corresponding to each dimming voltage are recorded, including:

[0018] The dimming voltage is controlled to start from 0V and increase by one step value each time. After the operating current, operating voltage, and power factor of the LED street light stabilize, the current dimming voltage and the corresponding active power are recorded. and power factor ;

[0019] The dimming voltage is controlled starting from 10V and decreased by one step value each time. After the operating current, operating voltage, and power factor of the LED street light stabilize, the current dimming voltage and the corresponding active power are recorded. and power factor .

[0020] Furthermore, the process of stabilizing the operating current, operating voltage, and power factor of the LED street light specifically involves: adjusting the dimming voltage to the corresponding dimming voltage step value, delaying for 1 second, and recording the data only after the operating current, operating voltage, and power factor parameters have stabilized.

[0021] Furthermore, it also includes: recording the ratio of the actual output dimming voltage after adjustment to the target dimming voltage obtained by reverse matching; if the ratio exceeds the user-preset threshold, an aging alarm signal is issued to indicate that the LED street light is aging.

[0022] In a second aspect, the present invention provides a street light dimming system for implementing the street light dimming method of the first aspect, comprising:

[0023] The dimming controller is used to perform control logic for initialization, dimming voltage step division, calculation of average active power P1 and average power factor PF1, target power back lookup matching, and automatic brightness consistency adjustment.

[0024] The PWM output module is electrically connected with the dimming controller, and is used for generating a target dimming voltage of 0V to 10V according to a dimming control signal of the dimming controller;

[0025] The acquisition module is electrically connected with the dimming controller, and is used for acquiring a working current and a working voltage of the LED street lamp, and calculating an active power and a power factor, and transmitting the working current, the working voltage and the power factor to the dimming controller;

[0026] The storage module is electrically connected with the dimming controller, and is used for storing the dimming voltage power data table;

[0027] The communication module is electrically connected with the dimming controller, and is used for realizing data interaction between the dimming controller and an upper computer / server;

[0028] The LED driving module is electrically connected with the PWM output module at one end and is electrically connected with the LED street lamp at the other end, and is used for receiving a dimming voltage signal of the PWM output module and driving the LED street lamp to adjust brightness;

[0029] The power supply module is electrically connected with the dimming controller, the PWM output module, the acquisition module, the storage module, the communication module and the LED driving module, respectively, and is used for providing working power supply for the system.

[0030] Further, the PWM output module generates the target dimming voltage of 0V to 10V in the following manner: a micro control unit with a DAC output function is directly outputted, or a PWM signal is converted into the target dimming voltage by using a PWM signal and an RC low-pass filter.

[0031] Further, the acquisition module comprises a current sampling circuit, a voltage sampling circuit and a signal processing unit; the current sampling circuit adopts a shunt sampling mode, a current signal collected is amplified by an operational amplifier circuit, is converted into a digital signal by an ADC module, is combined with a voltage digital signal collected by the voltage sampling circuit, and the active power and the power factor are calculated by the signal processing unit.

[0032] In summary, the beneficial effects of the present application are as follows:

[0033] The application provides a street lamp dimming method, which comprises the following steps: dividing a dimming voltage step value, and bidirectionally scanning and collecting data; taking 0V to 10V continuous step value as a reference, respectively adjusting the dimming voltage from 0V to rise and from 10V to drop; collecting data and calculating the power and power factor mean value under the same voltage after the parameters are stable, effectively eliminating the power difference caused by the voltage rise and drop during the LED dimming, constructing a precise dimming voltage and power corresponding relationship data table, and realizing the precise correspondence between the dimming voltage and the output power; combining the target power reverse lookup voltage and the real-time automatic adjustment, outputting the target dimming voltage matching the target power according to the data table, and adjusting the brightness of the LED street lamp according to the target dimming voltage. Meanwhile, the actual power and the target power of the lamp are collected in real time and compared, if the deviation between the actual power and the target power is out of range, the voltage is automatically adjusted to compensate the power deviation caused by the aging of the lamp, and finally the problem of inconsistent brightness caused by the aging degree and the power difference caused by the voltage rise and drop of different lamps is eliminated. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiments of the application. For those skilled in the art, other drawings can also be obtained without creative labor on the premise of not deviating from the protection scope of the application.

[0035] Figure 1 A flow chart of a street lamp dimming method of the application;

[0036] Figure 2 A hardware architecture diagram of a street lamp dimming system of the application. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the application more clear, the following will combine the drawings in the embodiments of the application to clearly and completely describe the technical solutions in the embodiments of the application. It should be noted that, in this article, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or sequence between the entities or operations. If there is no conflict, the features in the application and the embodiments can be combined with each other, and all are within the protection scope of the application.

[0038] The detailed implementation process of the application is shown in the following embodiments.

[0039] Embodiment 1: refer to Figure 1 as shown, Figure 1 A flow chart of a street lamp dimming method of the application, the method of the embodiment comprises:

[0040] S1: initially set the dimming voltage of the LED street lamp to 0V, and divide the dimming voltage from 0V to 10V into multiple continuous dimming voltage step values;

[0041] S2: control the dimming voltage to gradually rise from 0V and gradually drop from 10V, and after each adjustment, wait for the current, voltage and power factor to stabilize, and record the active power and power factor corresponding to each dimming voltage respectively;

[0042] S3: for the same dimming voltage, calculate the average active power P1 and the average power factor PF1 corresponding to the rising scan and the falling scan;

[0043] S4: store each dimming voltage and the average active power P1 and the average power factor PF1 in association to form a dimming voltage-power data table;

[0044] S5: obtain the target power of the LED street lamp to be adjusted, and inversely query the target dimming voltage from the dimming voltage-power data table, and output a dimming control signal according to the target dimming voltage to control the brightness of the LED street lamp to be adjusted;

[0045] S6: real-time collection of the actual power of the LED street lamp to be adjusted, if the deviation of the actual power and the target power exceeds the preset allowable range, adjust the dimming voltage to make the deviation return to the preset allowable range, and ensure the consistency of the brightness.

[0046] The embodiment divides the dimming voltage step values and collects data by bidirectional scanning. First, take the continuous step values from 0V to 10V as the reference, adjust the dimming voltage from 0V up and 10V down respectively, collect data after the parameters are stable, and calculate the average power and power factor under the same voltage, effectively eliminate the power difference caused by the voltage rise and fall during LED dimming, construct a precise dimming voltage-power corresponding relationship data table, and realize the accurate correspondence between the dimming voltage and the output power. Then, by combining the target power with the voltage and real-time automatic adjustment, the target dimming voltage matching the target power is output according to the data table, and the brightness of the LED street lamp is adjusted according to the target dimming voltage. At the same time, the actual power of the lamp is collected in real time and compared with the target power, if the deviation exceeds the range, the voltage is automatically adjusted to compensate for the power deviation caused by the aging of the lamp, and finally the problem of inconsistent brightness caused by the aging degree and the power difference caused by the voltage rise and fall of different lamps is eliminated.

[0047] Further, in order to solve the problem of rough brightness adjustment and fuzzy voltage-power correspondence caused by too large traditional dimming step value, and improve the control precision of dimming voltage, the division method of dimming voltage step value in step S1 of the embodiment is to divide the dimming voltage from 0V to 10V into 1000 parts, and each step value is 0.01V.

[0048] The 0V-10V dimming voltage range is precisely divided into 1000 parts, so that each step value is reduced to 0.01V. This way, the adjustment range of the dimming voltage is more delicate, avoiding sudden changes in LED street lamp power and brightness caused by large voltage jumps, ensuring the smoothness of brightness adjustment, and providing high-density sampling nodes for establishing a precise correspondence between dimming voltage and active power, ensuring that each voltage level can match the accurate power value.

[0049] Further, to avoid the voltage-power correspondence deviation caused by one-way scanning, the dimming voltage is controlled to gradually increase from 0V and gradually decrease from 10V in step S2, and after each adjustment, the active power and power factor corresponding to each dimming voltage are recorded after the current, voltage and power factor are stable, including the following sub-steps:

[0050] S21: control the dimming voltage to start from 0V, increase by one dimming voltage step value each time, and record the current dimming voltage V, active power and power factor at the corresponding time after the working current, working voltage and power factor of the LED street lamp are stable and power factor .

[0051] S22: control the dimming voltage to start from 10V, decrease by one dimming voltage step value each time, and record the current dimming voltage V, active power and power factor at the corresponding time after the working current, working voltage and power factor of the LED street lamp are stable and power factor .

[0052] The embodiment clearly specifies the specific operation of bidirectional scanning, i.e. the upward scanning starts from 0V and gradually increases, the downward scanning starts from 10V and gradually decreases, and the data is recorded after the current, voltage and power factor are stable after each adjustment. This method can obtain the original data of active power and power factor in different scanning directions, providing complete and accurate data source for subsequent calculation of average value to eliminate directional deviation, avoiding distortion of the voltage-power correspondence caused by scanning direction, and ensuring the reliability of the data table.

[0053] For each step dimming voltage, the formulas for calculating the average active power P1 and the average power factor P1 are as follows:

[0054] ;

[0055] .

[0056] Further, in order to avoid the problem that the parameters are in a transient fluctuation state after the voltage is just adjusted, the collected data cannot reflect the stable working state of the street lamp, and the accuracy of the collected data is improved, the working current, the working voltage and the power factor of the LED street lamp are set to be stable, that is, after the dimming voltage is adjusted to the corresponding dimming voltage step value, a delay of 1s is set, and the working current, the working voltage and the power factor are recorded after the parameters are stable. By adopting the processing mode of delaying 1s after the voltage is adjusted, the data is recorded after the working current, the working voltage and the power factor of the LED street lamp are completely stable; this method can exclude the transient interference (such as capacitor charging, circuit response delay, etc.) after the voltage is suddenly changed, ensure that the data recorded each time can truly reflect the stable working state of the street lamp under the dimming voltage, provide high-quality data for subsequent calculation of the average value of the active power and the average value of the power factor, and further improve the accuracy of the dimming voltage-power data table.

[0057] Further, in order to realize the early warning of lamp aging, the method of the embodiment further includes the step S8 of recording the ratio of the adjusted actual output dimming voltage to the target dimming voltage obtained by reverse lookup matching; if the ratio exceeds the threshold value preset by the user, an aging alarm signal is sent out to prompt the LED street lamp aging.

[0058] The embodiment actively monitors the aging degree of the lamp by using the characteristic that a higher voltage is required to reach the target power after the lamp is aged, prompts the maintenance personnel to replace the aged lamp in advance, avoids the inconsistent brightness or sudden failure of the same section caused by the aging of the lamp, and reduces the operation and maintenance cost and the night lighting safety risk.

[0059] Embodiment 2: Refer to Figure 2 The embodiment of the application also provides a street lamp dimming system for realizing the street lamp dimming method of embodiment 1, the system comprises:

[0060] a dimming controller for executing the control logic of initialization, dimming voltage step division, calculation of the average value P1 of the active power and the average value PF1 of the power factor, target power reverse lookup matching and automatic brightness consistency adjustment;

[0061] a PWM output module electrically connected with the dimming controller, for generating a target dimming voltage of 0V to 10V according to the dimming control signal of the dimming controller;

[0062] a collection module electrically connected with the dimming controller, for collecting the working current and the working voltage of the LED street lamp, and calculating the active power and the power factor, and transmitting the working current, the working voltage and the power factor to the dimming controller;

[0063] a storage module electrically connected with the dimming controller, for storing the dimming voltage-power data table;

[0064] The communication module is electrically connected with the dimming controller and is used for realizing data interaction of the dimming controller with the upper computer / server.

[0065] The LED driving module is electrically connected with the PWM output module at one end and is electrically connected with the LED street lamp at the other end, and is used for receiving the dimming voltage signal of the PWM output module and driving the LED street lamp to adjust the brightness.

[0066] The power supply module is electrically connected with the dimming controller, the PWM output module, the acquisition module, the storage module, the communication module and the LED driving module respectively, and is used for providing working power supply for the system.

[0067] The dimming controller adopts a micro control unit (MCU) as a control core, and the preferred model is an STM32F3 series (such as STM32F303CCT6) or an ESP32-C3 series. The STM32F3 series has a 12-bit DAC output function, which can directly generate a 0~10V analog dimming voltage without additional conversion circuit, simplifying the hardware design.

[0068] The storage module can adopt an off-chip Flash memory (such as W25Q64JVPIQ, capacity 64Mbit) or an MCU built-in EEPROM (such as 2KB EEPROM of STM32F303). The storage module can also use a CRC32 check algorithm to check the stored data, calculate the check value each time it is written / read, and trigger data rewriting / error reporting if the check fails, avoiding control deviation caused by data damage.

[0069] The communication module selects different communication modes according to the application scenario: if it is applied in urban and rural road / industrial park scenarios, a LoRa module (such as SX1278) is preferred, which supports a maximum communication distance of 10km, is suitable for the characteristics of scattered deployment of street lamps, and does not need wiring. If it is applied in a smart city scenario, a 4G / Cat1 module (such as Yidong EC200S) is selected, which supports remote data uploading (such as uploading lamp power and temperature data once an hour) and remote control (such as remotely modifying the target power).

[0070] The communication module data interaction content includes uplink data and downlink data, wherein the uplink data includes the actual power of the lamp, the dimming voltage and the aging state; the downlink data includes the target power, the step value and the aging alarm threshold.

[0071] Further, in order to adapt to the hardware cost and dimming accuracy demand in different scenarios, solve the problem that a single voltage generation method cannot balance high precision and low cost, and expand the application range of the system. The embodiment adopts two ways to generate 0V to 10V target dimming voltage in the PWM output module, which are: using a micro control unit with DAC output function to directly output, or using PWM signal to cooperate with RC low pass filter to convert PWM signal into target dimming voltage.

[0072] Among them, the MCU with DAC output function directly output is a high-precision scheme, and the DAC directly output has high precision, which is suitable for scenes with high dimming accuracy requirements (such as municipal trunk roads). The PWM signal cooperates with the RC low pass filter to convert the analog voltage, which is a low-cost scheme. The PWM+RC scheme has low cost and simple hardware structure, and is suitable for scenes with limited budget (such as rural roads). This means can be flexibly selected according to the scene, and the embodiment will not be repeated here.

[0073] Further, the acquisition module of the embodiment includes a current sampling circuit, a voltage sampling circuit and a signal processing unit; the current sampling circuit adopts a shunt sampling method, the acquired current signal is amplified by an operational amplifier circuit, and then converted into a digital signal by an ADC module, and then combined with the voltage digital signal acquired by the voltage sampling circuit to calculate the active power and power factor through the signal processing unit.

[0074] Among them, the acquisition module adopts the process of collecting current signal by shunt sampling circuit, amplifying by operational amplifier circuit, and converting into digital signal by ADC module, and then combines with the voltage sampling signal to calculate the active power and power factor. Among them, the shunt sampling method has high precision and lower cost than Hall sampling, the operational amplifier amplification can solve the problem of sampling error caused by weak small current signal, and the ADC conversion realizes the digital processing of analog signal, finally ensures that the calculated active power and power factor are more accurate, and provides reliable data support for the subsequent control logic of the dimming controller.

[0075] The software control process includes five core links of initialization phase, voltage scanning and data acquisition phase, data storage phase, normal working phase and aging alarm phase, and the specific execution steps are as follows:

[0076] 2.1 Initialization phase

[0077] Execution time: after the system is powered on (such as the daily 18:00 power-on start of the street lamp), the time consumption is about 500ms;

[0078] Specific operation: MCU completes basic configuration: initialize PWM module (frequency 1 kHz, duty cycle 0%, corresponding initial dimming voltage 0V), ADC module (sampling rate 100 Hz, collect current / voltage signal), serial port (for communication with communication module), timer (timer 1 for 1 s delay, timer 2 for zero-crossing point capture);

[0079] Read storage module data: read historical dimming voltage-power data table from Flash / EEPROM, if it is the first power-on (no historical data), mark as needing to perform scanning; if it is not the first power-on, there is historical data, then directly enter the normal working stage;

[0080] Communication module initialization: LoRa / 4G module completes registration (such as 4G module searching for base station, time-consuming about 10s), reports system ready state to the server.

[0081] 2.2 Voltage scanning and data acquisition stage

[0082] Execution condition: triggered when the initialization stage marks that scanning needs to be performed, single scanning time-consuming about 2000s (1000 steps x 2 scans x 1s delay / step);

[0083] Rising scan (0V→10V): MCU controls PWM output module, starts dimming voltage from 0V, increases by 0.01V (1 step value) each time, for example, outputs 0V at step 1, 0.01V at step 2,..., 10V at step 1001; after adjusting each voltage, delay for 1s (wait for current, voltage, and power factor to be stable, avoid parameter fluctuation caused by voltage mutation).

[0084] The acquisition module collects current and voltage signals 10 times at each step (sampling interval 100ms), calculates the average value as the instantaneous current Iup and instantaneous voltage Vup, and then calculates the active power according to the formula;

[0085] The dimming voltage Vup of each step, , is temporarily stored in the MCU memory (such as array buff_up

[1001] ).

[0086] Downward scan (10V→0V): adjust PWM output module, start dimming voltage from 10V, decrease by 0.01V each time, for example, output 10V at step 1, 9.99V at step 2,..., 0V at step 1001; after each step delay for 1s, the acquisition module also collects parameters 10 times, calculates the instantaneous current Idown and instantaneous voltage Vdown, and obtains the active power , power factor ; the dimming voltage Vdown of each step, , Temporary storage to memory array buff_down

[1001] .

[0087] 2.3 Data processing and storage phase

[0088] Data processing: for each dimming voltage step value V (total 1001, 0V, 0.01V, …, 10V), extract the corresponding , and , from buff_up and buff_down.

[0089] Calculate the average value: active power average P1, power factor average PF1; for example, V=5V, =50W, =49.8W, then P1=49.9W; =0.92, =0.91, then PF1=0.915.

[0090] Data storage: write V-P1-PF1 data in order of V from small to large into the storage module, and write the data generation time (such as 2024-05-20 18:05:00) and CRC32 checksum;

[0091] After storage is complete, send a "data update complete" signal to the communication module. If it is a remote monitoring scenario, you can upload the data table summary (such as the voltage value corresponding to the maximum / minimum power) through 4G / LoRa.

[0092] 2.4 Normal working phase

[0093] Target power acquisition: (1) Local control scenario: input target power through the button on the streetlight pole (such as 50W, corresponding to 100% brightness); (2) Remote control scenario: receive the target power issued by the server (such as adjusting the target power to 30W after 23:00 at night, corresponding to 60% brightness);

[0094] Target dimming voltage lookup: read the dimming voltage-power data table from the storage module, find the P1 value closest to the target power; for example, if the target power is 49.8W, find the V=5V corresponding to P1=49.9W in the table, as the target dimming voltage. If the target power is not in the table (such as 49.8W has no complete matching value), use linear interpolation to calculate: for example, P1=49.9W corresponds to V=5V, P1=49.7W corresponds to V=4.99V, then 49.8W corresponds to V=4.995V;

[0095] Dimming control and real-time adjustment: MCU controls the PWM output module to output the target dimming voltage, and the LED driving module adjusts the LED current after receiving the signal to make the power stable at the target value;

[0096] Real-time acquisition: the acquisition module acquires the actual power Pn of the lamp every 500 ms;

[0097] Deviation judgment and adjustment: if the deviation of Pn and the target power exceeds the preset allowable range, the dimming voltage is automatically adjusted: if Pn < 47.5W (low brightness): increase the dimming voltage by 0.01V each time until Pn returns to 47.5~52.5W; if Pn > 52.5W (high brightness): reduce the dimming voltage by 0.01V each time until Pn returns to the allowable range.

[0098] 2.5 Aging alarm phase

[0099] Judgment logic: during the voltage adjustment process in the normal working phase, record the actual dimming voltage VF after each adjustment, for example, the target power 50W corresponds to the target dimming voltage = 5V, and the lamp needs to be adjusted to VF = 6V to make Pn = 50W due to aging;

[0100] Threshold setting: users can set the aging alarm threshold through the upper computer (usually set to 1.2, that is, VF / V_ > 1.2 triggers the alarm);

[0101] Alarm execution: when VF / V_ > 1.2, the MCU controls the communication module to send a lamp aging alarm signal to the server, and controls the red indicator light on the street lamp pole to flash (frequency 1Hz), prompting the maintenance personnel to replace the lamp; if not replaced in time, the system will automatically limit the maximum dimming voltage (such as not more than 9V) to avoid damage to the driver due to overload.

[0102] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent substitutions for part or all of the technical features; and these modifications or substitutions do not make the essence of the corresponding technical solution deviate from the scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for dimming streetlights, characterized in that, include: The initial dimming voltage of the LED street light is set to 0V, and the dimming voltage from 0V to 10V is divided into multiple consecutive dimming voltage step values. The dimming voltage is controlled to gradually increase from 0V and then gradually decrease from 10V. After each adjustment, the current, voltage and power factor are stabilized, and the active power and power factor corresponding to each dimming voltage are recorded. For the same dimming voltage, calculate the average active power P1 and the average power factor PF1 corresponding to its rising and falling scans; Each dimming voltage is associated with and stored in relation to the average active power P1 and the average power factor PF1, forming a dimming voltage power data table; Obtain the target power of the LED street light to be adjusted, find the target dimming voltage by reverse matching according to the dimming voltage power data table, and output a dimming control signal according to the target dimming voltage to control the brightness of the LED street light to be adjusted. The actual power of the LED street light to be adjusted is collected in real time. If the deviation between the actual power and the target power exceeds the preset allowable range, the dimming voltage is adjusted to bring the deviation back to the preset allowable range and ensure consistent brightness.

2. The street light dimming method according to claim 1, characterized in that, The dimming voltage step value is divided as follows: the dimming voltage range of 0V to 10V is divided into 1000 parts, and each step value is 0.01V.

3. The street light dimming method according to claim 1, characterized in that, The control dimming voltage is first scanned upwards gradually from 0V, then scanned downwards gradually from 10V. After each adjustment, once the current, voltage, and power factor stabilize, the active power and power factor corresponding to each dimming voltage are recorded, including: The dimming voltage is controlled to start from 0V and increase by one dimming voltage step value each time. After the operating current, operating voltage and power factor of the LED street light are stable, the current dimming voltage, the active power and power factor at the corresponding time are recorded. The dimming voltage is controlled to start from 10V and decrease by one dimming voltage step value each time. After the operating current, operating voltage and power factor of the LED street light stabilize, the current dimming voltage, the active power and power factor at the corresponding time are recorded.

4. A street light dimming method according to claim 3, characterized in that, The process of stabilizing the operating current, operating voltage, and power factor of the LED street light is as follows: after adjusting the dimming voltage to the corresponding dimming voltage step value, delay for 1 second, and record the data after the operating current, operating voltage, and power factor parameters have stabilized.

5. A street light dimming method according to claim 1, characterized in that, Also includes: Record the ratio of the actual output dimming voltage after adjustment to the target dimming voltage obtained by reverse matching; If the ratio exceeds the user-preset threshold, an aging alarm signal will be issued to indicate that the LED street light is aging.

6. A street light dimming system for implementing the street light dimming method according to any one of claims 1-5, characterized in that, include: The dimming controller is used to perform control logic for initialization, dimming voltage step division, calculation of average active power P1 and average power factor PF1, target power back lookup matching, and automatic brightness consistency adjustment. The PWM output module is electrically connected to the dimming controller and is used to generate a target dimming voltage of 0V to 10V according to the dimming control signal of the dimming controller. The acquisition module, which is electrically connected to the dimming controller, is used to acquire the operating current and operating voltage of the LED street light, calculate the active power and power factor, and transmit the operating current, operating voltage and power factor to the dimming controller. The storage module, electrically connected to the dimming controller, is used to store the dimming voltage and power data table; The communication module is electrically connected to the dimming controller and is used to realize data interaction between the dimming controller and the host computer / server; The LED driver module is electrically connected at one end to the PWM output module and at the other end to the LED street light. It is used to receive the dimming voltage signal from the PWM output module and drive the LED street light to adjust its brightness. The power supply module is electrically connected to the dimming controller, PWM output module, acquisition module, storage module, communication module and LED driver module, respectively, and is used to provide working power for the system.

7. The street light dimming system according to claim 6, characterized in that, The PWM output module generates the target dimming voltage from 0V to 10V in the following ways: it directly outputs the voltage using a microcontroller unit with DAC output function, or it converts the PWM signal into the target dimming voltage using a PWM signal in conjunction with an RC low-pass filter.

8. The street light dimming system according to claim 6, characterized in that, The acquisition module includes a current sampling circuit, a voltage sampling circuit, and a signal processing unit. The current sampling circuit adopts a shunt sampling method. The acquired current signal is amplified by the operational amplifier circuit, converted into a digital signal by the ADC module, and then combined with the voltage digital signal acquired by the voltage sampling circuit. The active power and power factor are calculated by the signal processing unit.

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