Design of LED Street Light Energy Saving Monitoring System

1 Introduction

The main problems of street lighting in cities, especially small and medium-sized cities, are that the overall planning is lagging behind, the lighting control methods and management means are backward, and the electrical appliances and lamps used have low technological content. This paper uses high-brightness LED as the core device of street lights and designs a street light monitoring system. The current and voltage of street lights are collected from the single-chip microcomputer on site and then transmitted through the host and the upper computer via GPRS data, thus achieving the purpose of "remote control, remote measurement, and remote communication".

2 System Working Principle and Hardware Design

2.1 System overall structure design

The overall structure is shown in Figure 1. The system mainly consists of three parts: LED energy-saving control center, China Mobile GPRS network and street light RTU.

Figure 1 Overall structure diagram

The street light monitoring center includes 3131P Modem module, street light monitoring RTU, online monitoring terminal control box, GPRS module, single light detection controller, etc.

In this monitoring system, the controller unit is connected to the mobile GPRS wireless terminal through RS-232, the computer in the monitoring center is connected to the mobile GPRS through a special router, the street light RTU collects power signals, and finally the mobile GPRS network transmits the data to the monitoring center. The monitoring center is connected to the UPS power supply and adopts the UPS power supply design, so that the monitoring center can continue to work when the power is off, ensuring the reliable operation of the system.

As the main core part of the whole system, the monitoring center not only needs to communicate closely with the upper RTU, but also needs to classify, store, process and transmit the collected data. At the same time, it needs to give corresponding alarms (voice, sound and light) and the information of the node street lights required to be located. In addition, it can send fault information and (or) street light maintenance information to the mobile phones of relevant designated personnel via GPRS short messages to obtain road section information in a timely manner.

2.2 LED drive circuit design

The LED lighting drive circuit mainly includes two parts: the drive circuit and the over-temperature protection circuit. The MAX5033 chip is mainly used in the design of the drive circuit, which can provide an output current of up to 500mA. The MAX5033D provides an adjustable voltage of 1.25~13.2V.

The chip used in the over-temperature protection circuit is MBI1801. The chip has a temperature sensor inside that can sense the temperature of the chip. The output current can be automatically adjusted through the R-EXT pin, so that the current on the LED can be changed, thereby reducing the temperature of the LED and playing the role of over-temperature protection. Based on the above advantages, the chips based on MAX5033 and MBI1801 are selected to implement the drive circuit.

The designed LED drive circuit is shown in Figure 2, which is mainly divided into three parts: power supply circuit, drive circuit and over-temperature protection circuit. The power supply circuit is mainly composed of two modules: transformer and rectifier bridge; the drive circuit is mainly composed of MAX5033 module and voltage regulator module; the over-temperature protection circuit is mainly composed of MBI1801, thermal sensing module and LED.

Figure 2 LED driver circuit diagram

3 System Software Design

See Figure 3. When the 7188XA module is started, there is an automatic run file that is linked to the database. This file runs automatically as soon as the 7188XA is powered on.

In this system, the visual development tool Visual Basic 6.0 is used for development. The main interface of the monitoring center is shown in Figure 4.

Figure 3 Software system block diagram

Figure 4 LED energy-saving control center software interface

For the application environment of street lamp computer wireless monitoring system, the main functions of the system are:

(1) Remote control: operating parameters of each node and road section, such as turning lights on/off, illumination, etc.;

(2) Telemetry: Manually and automatically collect parameters of each monitoring point of the street lighting system;

(3) Monitoring: monitoring of road sections, street lights, etc. and their surrounding areas;

(4) Alarm information: It can provide automatic alarm query of multiple parameters: such as high alarm and low alarm.

(5) Data query: You can query the relevant historical data of a certain node and/or road section at any minute/hour/day/month/year; 4 Conclusion.

This system applies GPRS and high-power LED technology to the street lamp energy-saving monitoring system, solving the actual energy-saving problem that cannot be solved by the current Chinese street lamp control, realizing "three remotes" and data collection and monitoring, and realizing intelligent lighting. The monitoring center can obtain feedback information in a timely manner, perform fault inversion, reduce operating costs, reduce personnel expenses, and achieve the purpose of economic energy saving.

The main control and energy-saving technologies of this system can be applied not only to street lamp management, but also to more fields, such as heating engineering, rail transportation, etc. Provide them with useful suggestions to improve work efficiency.