A color temperature changeable street lamp control system based on power line carrier communication

Abstract

The utility model discloses a kind of based on power line carrier communication color temperature changing street lamp control system, including three-way PWM pulse width modulation circuit, 0-5V brightness control circuit and LED street lamp driver, three-way PWM pulse width modulation circuit includes two-way variable color temperature control circuit and one-way brightness variable digital control circuit, three-way PWM pulse width modulation circuit and 0-5V brightness control circuit are connected LED street lamp driver respectively, LED street lamp driver connects variable color temperature street lamp, realize the intelligent control to variable color temperature street lamp, wherein, two-way variable color temperature control circuit respectively controls the luminous intensity of variable color temperature street lamp by complementary PWM pulse width modulation signal, two-way light group of high color temperature and low color temperature respectively controls its luminous intensity by two-way complementary PWM pulse width modulation circuit, when one-way luminous variable is strong, another luminous variable is weak, realize change color temperature, system with MCU microprocessor U4 and power carrier 485 communication chip U5 constitute the basic circuit of power carrier communication.

Description

Technical Field

[0001] This utility model relates to the field of color temperature changing street light control technology, specifically, to a color temperature changing street light control system based on power line carrier communication. Background Technology

[0002] To provide pedestrians and drivers with greater comfort under different seasons and climates, color-temperature variable streetlights are a good choice. However, unlike LED streetlights with fixed color temperature and brightness that only require on / off control via a switch controller, color-temperature variable streetlights require control through variations in color temperature and brightness. Therefore, as an integrated terminal device, the color-temperature and brightness variable streetlight needs to receive not only on / off control signals but also signals for adjusting color temperature and brightness. This necessitates that the streetlight device have the ability to communicate with a special switch controller or centralized controller. To achieve this, existing solutions involve using wireless communication methods for the streetlight controller, such as using an NB-IoT module for remote IoT control or a Zigbee module for local control. While this approach has its advantages, the streetlight controller is generally assembled with the color-temperature variable streetlight, forming an integrated streetlight device. These communication modules, being built into the streetlight device, result in relatively high equipment and operating costs (when using NB-IoT), and the device's manufacturing process must ensure that the antenna can reliably receive wireless signals, making the device structure somewhat complex. Summary of the Invention

[0003] In view of the problems in related technologies, this utility model proposes a color temperature street light control system based on power line carrier communication to overcome the above-mentioned technical problems existing in the existing related technologies.

[0004] Therefore, the specific technical solution adopted by this utility model is as follows:

[0005] A power line carrier communication-based color-temperature street light control system includes a three-channel PWM pulse width modulation circuit, a 0-5V brightness control circuit, and an LED street light driver. The three-channel PWM pulse width modulation circuit includes two color-temperature control circuits and one brightness-changing digital control circuit. The three-channel PWM pulse width modulation circuit and the 0-5V brightness control circuit are respectively connected to the LED street light driver, and the LED street light driver is connected to the color-temperature street light to realize intelligent control of the color-temperature street light. Among them, the two color-temperature control circuits control the luminous intensity of the color-temperature street light through complementary PWM pulse width modulation signals. The system uses an MCU microprocessor U4 and a power line carrier 485 communication chip U5 to form the basic circuit of power line carrier communication.

[0006] Furthermore, the system uses MCU microprocessor U4 as the main control chip. Pins 4, 14, and 15 of U4 are connected to pins 5, 1, and 2 of switch P2, respectively. Pin 1 of U4 is connected to SGND. Pin 16 of U4 is connected to voltage V1. Pin 14 of U4 is connected to pin 1 of chip U5 and pin 1 of connector P2. Pin 15 of U4 is connected to pin 4 of U5 and pin 2 of P2. Pin 5 of U4 is connected to pin 2 of U5 and one end of R10. The other end of R10 is connected to V1. Pins 3, 7, 8, and 9 of U4 are connected to one end of R5, R4, R15, and R6, respectively. The other ends of R4, R5, and R6 are connected to the anode terminals of optocouplers U1 to U3, respectively. The other end of R15 is connected to the gate of transistor Q4 and one end of C10. One end of C1 and C8 is connected to SGND, and the other end is connected to V1. The remaining pins of U4 are not connected to external components. The cathodes of U1-U3 are all connected to SGND, the collector outputs are all connected to voltage V2, and the emitter outputs are connected to R7-R9 and the bases of transistors Q1-Q3, respectively. The other ends of R7-R9 and the emitters of Q1-Q3 are all connected to GND. The collectors of Q1-Q3 are connected to one end of R1-R3 and pins 5, 4, and 3 of connector P1, respectively. The other ends of R1-R3 are all connected to V2. The source of Q4 and the other end of C10 are connected to SGND. The drain of Q4 is connected to the cathode of U6. The anode of operational amplifier U6 is connected to one end of R20, and the other end of R20 is connected to V1. The emitter of U6 is connected to the gate of transistor Q5 and one end of R18. The other end of R18 and the source of Q5 are connected to GND. The drain of Q5 is connected to one end of R13 and pin 2 of P1. The other end of R13 is connected to V2. Pin 1 of P1 is connected to GND. Pins 5 and 8 of U5 are connected to SGND and V1 respectively; pin 7 is connected to one end of R11 and one end of C2; pin 6 is connected to the other end of R11 and one end of C3; the other end of C2 is connected to one end of L1, and the other end of C3 is connected to the other end of L2; the other ends of L1 and L2 are connected to pins 2 and 1 of connector P3. Pin 1 of chip U7 is connected to one end of R21 and C15; pin 2 is connected to one end of R17; pin 3 is connected to the other end of R17 and V1; pin 4 is connected to one end of R14 and R19; pin 5, R21, and the other end of C15 are connected to SGND; pin 6 is connected to the gate of Q6; pin 7 is connected to the positive terminal of C12; and pin 8 is connected to one end of R16. The two AC input terminals of rectifier bridge D2 are connected to both ends of RV1 and pins 1 and 2 of P3 respectively; the DC positive terminal is connected to the positive terminal of C11; and the DC negative terminal and the negative terminal of C11 are connected to SGND. Rectifier bridge D2 consists of four diodes. The circuit is connected as follows: the other end of R16 is connected to the positive terminal of C11, one end of inductor L3, and the negative terminal of diode D1; the other end of L3 is connected to the negative terminal of C9 and the drain of transistor Q6; the positive terminal of D1 is connected to the positive terminal of C9 and the negative terminal of diode D3, the positive terminal of D3 is connected to the positive terminal of diode D4 and one end of inductor L4, the other end of L4, the source of Q6, and the other end of R19 are connected to SGND; the other end of R14 is connected to the negative terminal of D4, the positive terminal of C14, and one end of C13; the negative terminal of C14 and the other end of C13 are connected to SGNG.Pin 2 of DC-DC module M1 is connected to V1, pin 1 is connected to C8 and grounded, and pins 3 and 4 are connected to C6 and C7 respectively. C6 and C7 are high and low frequency filter capacitors of 5V isolation power supply. DC-DC module M1 is an isolation power supply module.

[0007] Furthermore, chip U7 is a non-isolated power controller.

[0008] The beneficial effects of this application are as follows:

[0009] 1. This application includes three PWM pulse width modulation signals and one 0-5V brightness control signal. Based on the working principle of color-temperature variable LED lights, the two light groups with high (white) and low (yellow) color temperatures are controlled by two complementary PWM pulse width modulation signals to control their luminous intensity. When one light source becomes stronger, the other must become weaker, and the mixing effect changes the color temperature. Therefore, two of the three PWM signals provided are complementary signals used for color temperature control, and the other PWM signal or one brightness control signal is used to control brightness. Unlike wireless communication, this invention uses only an OOK modulation 485 compatible chip, applying a carrier signal to the power line through a capacitor and inductor coupling circuit to achieve power line carrier communication. Thus, remote control of color-temperature variable LED streetlights is achieved by transmitting signals through the power line supplied to the streetlight. Because the wireless communication module is omitted and no dedicated power line carrier communication module is used, the circuit structure becomes very simple, resulting in lower equipment costs.

[0010] 2. In order to improve the safety and reliability of the controller circuit and the street light circuit, this application adopts electrical isolation technology between the two circuits to achieve isolation between signal transmission and power supply;

[0011] 3. This application employs the THVD8010 485 communication chip with OOK modulation function, connecting the microprocessor and the capacitors and inductors of the power supply line to realize near- and long-range intelligent communication control of the color-temperature street light. Simultaneously, the low-voltage DC power supply for the circuit is composed of a dedicated non-isolated offline power controller chip, UCC3889, combined with relevant auxiliary circuitry. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a circuit diagram of the color temperature street light control system based on power line carrier communication according to this application;

[0014] Figure 2 yes Figure 1 Local magnification Figure 1 ;

[0015] Figure 3 yes Figure 1 Local magnification Figure 2 ;

[0016] Figure 4 yes Figure 1 Local magnification Figure 3 . Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] like Figure 1-4 As shown, according to an embodiment of this utility model, a color-changing street light control system based on power line carrier communication is provided. The system uses MCU microprocessor U4 as the main control chip. Pins 4, 14, and 15 of U4 are connected to pins 5, 1, and 2 of P2, respectively. Pin 1 is connected to SGND. Pin 16 is connected to V1. Pin 14 is connected to pins 1 of U5 and P2. Pin 15 is connected to pins 4 of U5 and P2. Pin 5 is connected to pin 2 of U5 and one end of R10. The other end of R10 is connected to V1. Pins 3, 7, 8, and 9 are connected to one end of R5, R4, R15, and R6, respectively. The other ends of R4, R5, and R6 are connected to the anode terminals of optocouplers U1 to U3, respectively. The other end of R15 is connected to the gate of Q4 and one end of C10. One end of C1 and C8 is connected to SGND, and the other end is connected to V1. The remaining pins of U4 are not connected to external components.

[0019] The cathodes of U1-U3 are all connected to SGND, the collector outputs are all connected to V2, and the emitter outputs are connected to the bases of R7-R9 and Q1-Q3 respectively. The other ends of R7-R9 and the emitters of Q1-Q3 are all connected to GND. The collectors of Q1-Q3 are connected to one end of R1-R3 and pins 5, 4, and 3 of P1 respectively. The other ends of R1-R3 are all connected to V2. The source of Q4 and the other end of C10 are connected to SGND. The drain of Q4 is connected to the cathode of U6. The anode of U6 is connected to one end of R20, and the other end of R20 is connected to V1. The emitter of U6 is connected to the gate of Q5 and one end of R18. The other end of R18 and the source of Q5 are connected to GND. The drain of Q5 is connected to one end of R13 and pin 2 of P1. The other end of R13 is connected to V2. Pin 1 of P1 is connected to GND.

[0020] Pins 5 and 8 of U5 are connected to SGND and V1 respectively. Pin 7 is connected to one end of R11 and one end of C2. Pin 6 is connected to the other end of R11 and one end of C3. The other end of C2 is connected to one end of L1, and the other end of C3 is connected to the other end of L2. The other ends of L1 and L2 are connected to pins 2 and 1 of P3.

[0021] Pin 1 of U7 is connected to one end of R21 and C15, pin 2 is connected to one end of R17, pin 3 is connected to the other end of R17 and V1, pin 4 is connected to one end of R14 and R19, pin 5, the other end of R21 and C15 is connected to SGND, pin 6 is connected to the gate of Q6, pin 7 is connected to the positive terminal of C12, and pin 8 is connected to one end of R16; the two AC input terminals of D2 are connected to the two ends of RV1 and pins 1 and 2 of P3 respectively, the DC positive terminal is connected to the positive terminal of C11, and the DC negative terminal and the negative terminal of C11 are connected to SGND; The other end of R16 is connected to the positive terminal of C11, one end of L3, and the negative terminal of D1; the other end of L3 is connected to the negative terminal of C9 and the drain of Q6; the positive terminal of D1 is connected to the positive terminal of C9 and the negative terminal of D3, the positive terminal of D3 is connected to the positive terminal of D4 and one end of L4, the other end of L4, the source of Q6, and the other end of R19 are connected to SGND; the other end of R14 is connected to the negative terminal of D4, the positive terminal of C14, and one end of C13 (i.e., V1); the negative terminal of C14 and the other end of C13 are connected to SGNG.

[0022] The working principle of this color-temperature street light control system based on power line carrier communication is as follows:

[0023] The system is based on the U4 microprocessor HR7P201FHS3 and the U5 power line carrier 485 communication chip THVD8010. These two chips constitute the basic circuit for power line carrier communication. U5 is a 485 chip with OOK modulation function. Its A and B pins (pins 6 and 7) are connected in parallel with a matching resistor R11, and then connected to the power line via high-voltage isolation capacitors C2 and C3 and filter inductors L1 and L2. The modulation signal generated by U5 is transmitted to the power line through this connection, realizing the power line carrier communication function. The R pin (pin 1) of U5 is the receiving end, connected to the RX pin (pin 14) of U4; the D pin (pin 4) is the transmitting end, connected to the TX pin (pin 15) of U4; the MODE pin (pin 2) of U5 is the transmit / receive control pin, connected to the PA3 (pin 5) of U4 through a pull-up resistor R10. When P... The A3 pin's high / low level change switches between transmit and receive functions; the FSET pin (pin 3) of U5 is connected to R12 to set the OOK carrier frequency, with C5 connected in parallel as an interference decoupling capacitor; C1, C4, and C8 are connected between the power supply and ground pins of U5 and U4 chips respectively, serving as decoupling capacitors for the power supply terminals of U5 and U4; the RX (ISPD), TX (ISPC), and NRST pins of U4 are connected to the download socket P2, and the program is downloaded to the chip through P2 after completion; the PWM10, PWM11, and PWM21 ports of U4 are connected to the input terminals of high-speed optocouplers U1, U2, and U3 through resistors R4 to R6. The PWM10, PWM11, and PWM21 ports of U4 output PWM modulation signals, where PWM10 and PWM11 are complementary PWM signals, and this set of complementary signals is key to color temperature control. Resistors R4-R6 limit the input current of the optocoupler. When the optocoupler receives a PWM signal, it is isolated by the optocoupler, and its output is driven by transistors Q1-Q3 and led out to the PWM1-PWM3 ports of the P1 socket. PWM1 and PWM2 are complementary outputs and can be connected to the color temperature control terminal of a color-temperature LED street light; PWM3 is for brightness control and can be connected to the brightness control terminal of a color-temperature LED street light. Resistors R7-R9 are bias resistors for transistors Q1-Q3, and resistors R1-R3 are collector resistors for transistors Q1-Q3, providing the operating point of the transistors. The PWM20 port of U4 also outputs a PWM modulation signal. However, this signal is filtered by a low-pass filter composed of resistor R15 and capacitor C10 to form a variable analog signal. Then, it drives optocoupler U6 through the MOSFET of Q4, and after isolation by U6 and amplification by MOSFET Q5, it is connected to the ADO terminal of the P1 socket to form a 0-5V analog control signal. This analog signal can also be used for brightness control of LED street lights. Resistor R20 limits the input current of U6, resistor R18 is the bias resistor of Q5, and R13 is the drain resistor of Q5, providing the operating point of Q5.

[0024] The U7, model UCC3889, is a non-isolated power controller. Through its circuit structure, it converts 220V AC power to +5V DC power to provide operating power for the entire street light controller circuit. The 220V AC input first passes through RV1 varistor, which suppresses transient high voltages generated by the power line. Then, it is rectified by rectifier bridge D2 and filtered by capacitor C11, forming approximately 310V DC high voltage to power the U7 power controller. R16 is a charging current-limiting resistor, internally charging C12 to establish an operating voltage of approximately 9V VCC. C15 and R21 form the oscillator's charging and discharging circuit, and together with R16 and R17, they determine the power controller's switching frequency. R14 and R19 are connected from the output terminal to form a voltage divider circuit, creating a closed-loop voltage regulator circuit. Based on the chip's internal 2.5V reference voltage, the resistance values ​​of R14 and R19 are equal, thus allowing adjustment to a 5V output power. L3, L4, C9, D1, Q6, D3, D4, C13, and C14 constitute an improved SEPIC converter circuit. When Q6 is turned on, L3 stores energy, while the previously stored energy in C9 is released to L4. When Q6 is turned off, L3 releases energy through C9 and D1 (at this moment, C9 is equivalent to storing energy), while L4 releases energy through D4, C13, and C14. Because the switching frequency is very high, a 5V DC voltage is established at the output terminal V1 to power the entire circuit chip.

[0025] M1 is the DY5S05 isolation power supply module, which isolates the operating power supply of the controller section from the operating power supply of the output signal section. Through the isolation effect of the optocoupler, the signal circuit output to the LED street light section is completely isolated from the power supply and ground of the main circuit. Capacitors C6 and C7 are high and low frequency filter capacitors for the 5V isolation power supply.

[0026] The component models or specifications of this power line carrier communication-based color temperature street light control system are as follows:

[0027] Resistor section:

[0028] R1-R3, R7-R9, R14, R18, R19: 10KΩ; R4-R6, R20: 1KΩ; R10: 4.7KΩ; R11: 60Ω; R1 2: 50KΩ; R13, R15: 5.1KΩ; R16: 330KΩ; R17: 150KΩ; R21: 1MΩ; RV1: 471D (varistor).

[0029] Capacitor section:

[0030] C1, C4, C6, C10, C13: 104mm ceramic capacitor; C2, C3: 100pF / 400V ceramic capacitor; C5: 100pF ceramic capacitor; C7: 220uF / 16V electrolytic capacitor; C8: 8uF ceramic capacitor; C9: 2uF / 150V electrolytic capacitor; C11: 4.7uF / 400V electrolytic capacitor; C12: 1uF / 25V electrolytic capacitor; C14: 220uF / 25V electrolytic capacitor; C15: 150pF ceramic capacitor.

[0031] Inductor section:

[0032] L1, L2: 100uH; L3: 2mH; L4: 470uH.

[0033] II. Transistor Section:

[0034] D1, D3: High-frequency diode IN4937; D2: Rectifier bridge LDD06; D4: High-frequency diode IN4935; Q1~Q3: Transistor 2N5551; MOSFET section: Q4~Q5: N-channel MOSFET 2N7002; Q6: N-channel MOSFET HM4N60.

[0035] Integrated circuit section:

[0036] U1-U3, U6: High-speed optocoupler 629P821; U4: Microprocessor HR7P201FHS3; U5: OOK power line carrier 485 communication chip THVD8010; U7: Offline (non-isolated) power controller UCC3889.

[0037] Module section:

[0038] M1: DC-DC module DY5S05.

[0039] Connector section:

[0040] P1: 5-pin PWM and analog signal output socket; P2: Microprocessor simulation download socket; P3: AC 220V power input socket.

[0041] Furthermore, the power line carrier circuit for this color-changing street light control system based on power line carrier communication can utilize specialized modules, such as TXZX13 and TCC081E. Additionally, other types of microprocessors can be used, such as the STM8S series chips.

[0042] In summary, this power line carrier communication-based color temperature street light control system features two complementary PWM signal outputs for color temperature control; one PWM output for brightness control; one analog signal output for brightness control; isolated control signal outputs and electrical isolation between power supplies; OOK modulation function and 485 power line carrier communication function, enabling near- and long-range intelligent control; and a dedicated non-isolated power controller chip to construct a DC low-voltage power supply circuit, ensuring safety, reliability, and effective color temperature street light control.

[0043] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A color-temperature variable street light control system based on power line carrier communication, characterized in that, The system includes a three-channel PWM pulse width modulation circuit, a 0-5V brightness control circuit, and an LED street light driver. The three-channel PWM pulse width modulation circuit includes two color temperature control circuits and one brightness control circuit. The three-channel PWM pulse width modulation circuit and the 0-5V brightness control circuit are respectively connected to the LED street light driver, and the LED street light driver is connected to the color temperature street light to realize intelligent control of the color temperature street light. Among them, the two color temperature control circuits control the luminous intensity of the color temperature street light through complementary PWM pulse width modulation signals. The system uses an MCU microprocessor U4 and a power line carrier 485 communication chip U5 to form the basic circuit of power line carrier communication.

2. The color temperature street light control system based on power line carrier communication according to claim 1, characterized in that, The system uses MCU microprocessor U4 as the main control chip. Pins 4, 14, and 15 of U4 are connected to pins 5, 1, and 2 of switch P2, respectively. Pin 1 of U4 is connected to SGND. Pin 16 of U4 is connected to voltage V1. Pin 14 of U4 is connected to pin 1 of chip U5 and pin 1 of connector P2. Pin 15 of U4 is connected to pin 4 of U5 and pin 2 of P2. Pin 5 of U4 is connected to pin 2 of U5 and one end of R10. The other end of R10 is connected to V1. Pins 3, 7, 8, and 9 of U4 are connected to one end of R5, R4, R15, and R6, respectively. The other ends of R4, R5, and R6 are connected to the anode terminals of optocouplers U1 to U3, respectively. The other end of R15 is connected to the gate of transistor Q4 and one end of C10. One end of C1 and C8 is connected to SGND, and the other end is connected to V1.

3. A color-temperature street light control system based on power line carrier communication according to claim 2, characterized in that, The cathodes of U1-U3 are all connected to SGND, the collector outputs are all connected to voltage V2, and the emitter outputs are connected to R7-R9 and the bases of transistors Q1-Q3, respectively. The other ends of R7-R9 and the emitters of Q1-Q3 are all connected to GND. The collectors of Q1-Q3 are connected to one end of R1-R3 and pins 5, 4, and 3 of connector P1, respectively. The other ends of R1-R3 are all connected to V2. The source of Q4 and the other end of C10 are connected to SGND. The drain of Q4 is connected to the cathode of U6. The anode of operational amplifier U6 is connected to one end of R20, and the other end of R20 is connected to V1. The emitter of U6 is connected to the gate of transistor Q5 and one end of R18. The other end of R18 and the source of Q5 are connected to GND. The drain of Q5 is connected to one end of R13 and pin 2 of P1. The other end of R13 is connected to V2. Pin 1 of P1 is connected to GND.

4. A color-temperature street light control system based on power line carrier communication according to claim 3, characterized in that, Pins 5 and 8 of U5 are connected to SGND and V1 respectively. Pin 7 is connected to one end of R11 and one end of C2. Pin 6 is connected to the other end of R11 and one end of C3. The other end of C2 is connected to one end of L1, and the other end of C3 is connected to the other end of L2. The other ends of L1 and L2 are connected to pins 2 and 1 of connector P3.

5. A color-temperature street light control system based on power line carrier communication according to claim 4, characterized in that, Pin 1 of chip U7 is connected to one end of resistor R21 and capacitor C15; pin 2 is connected to one end of resistor R17; pin 3 is connected to the other end of resistor R17 and capacitor V1; pin 4 is connected to one end of resistors R14 and R19; pin 5, the other end of resistor R21 and capacitor C15, is connected to SGND; pin 6 is connected to the gate of capacitor Q6; pin 7 is connected to the positive terminal of capacitor C12; and pin 8 is connected to one end of resistor R16. The two AC input terminals of rectifier bridge D2 are connected to the two ends of RV1 and pins 1 and 2 of capacitor P3, respectively. The DC positive terminal is connected to the positive terminal of capacitor C11, and the DC negative terminal and the negative terminal of capacitor C11 are connected to SGND. Rectifier bridge D2 consists of four diodes. The circuit is connected as follows: the other end of R16 is connected to the positive terminal of C11, one end of inductor L3, and the negative terminal of diode D1; the other end of L3 is connected to the negative terminal of C9 and the drain of transistor Q6; the positive terminal of D1 is connected to the positive terminal of C9 and the negative terminal of diode D3, the positive terminal of D3 is connected to the positive terminal of diode D4 and one end of inductor L4, the other end of L4, the source of Q6, and the other end of R19 are connected to SGND; the other end of R14 is connected to the negative terminal of D4, the positive terminal of C14, and one end of C13; the negative terminal of C14 and the other end of C13 are connected to SGNG.

6. A color-temperature street light control system based on power line carrier communication according to claim 5, characterized in that, Chip U7 is a non-isolated power controller.

7. A color-temperature street light control system based on power line carrier communication according to claim 6, characterized in that, Pin 2 of DC-DC module M1 is connected to V1, pin 1 is connected to C8 and grounded, and pins 3 and 4 are connected to C6 and C7 respectively. C6 and C7 are high and low frequency filter capacitors of 5V isolation power supply. DC-DC module M1 is an isolation power supply module.

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