Working principle of the solar led street lamp, solar energy is the most direct the most common and most clean energy, solar energy as a huge amount of renewable energy, led the spectra of almost all concentrated in the visible light spectrum, high luminous efficiency, so it is generally believe that 4/5 energy-saving lamps save energy is a great invention, but the led energy saving a quarter than energy-saving lamps, Such a good resource but our production of LED street lamp development of the new direction!

Solar LED street lighting integrates the advantages of solar energy and LED.

1. System introduction

1.1 Introduction to basic system composition

The system is composed of solar cell component (including bracket), LED lamp holder, control box (with controller, battery) and lamp pole several parts; Solar panel light efficiency up to 127Wp/m2, high efficiency, for the wind resistance design of the system is very beneficial; In the lamp holder part, 1W white LED and 1W yellow LED are integrated on the printed circuit board and arranged in a certain spacing dot matrix as the plane source.

The control box is made of stainless steel, beautiful and durable; Maintenance-free lead acid battery and charge and discharge controller are placed in the control box. This system uses valve-controlled sealed lead-acid battery, which is also called "maintenance-free battery" because of its little maintenance, which is beneficial to reduce the maintenance cost of the system. The design of the charge and discharge controller takes into account the complete functions (with light control, time control, overcharge protection, overdischarge protection and reverse connection protection, etc.) and cost control, to achieve a high cost performance.

1.2 Introduction to the working principle of solar LED street light

Working principle of the system is simple, the use of light born V effect principle of solar cells, solar panels during the day to receive solar radiation and translated into electricity output, after stored in the storage battery charging and discharging controller, the night when the illumination was gradually reduced to about 10 lux, solar panels around the open circuit voltage of 4.5 V, charge and discharge controller detects the voltage value of the action, The battery discharges the lamp cap. After the battery discharges for 8.5 hours, the charge and discharge controller starts to discharge the battery. The main function of charge and discharge controller is to protect the battery.

2. Design idea of solar LED street lamp system

Compared with general solar lighting, the basic principle of solar street lamp design is the same, but there are more links to consider. The following will take Hong Kong True Mingli Group Co., LTD., this solar LED high-power street lamp as an example, divided into several aspects to do analysis.

2.1 Selection of solar cell modules

Design requirements: Guangzhou area, load input voltage 24V power consumption 34.5W, daily working hours 8.5h, ensure continuous rainy days 7 days.

(1) The average annual radiation in Guangzhou in the past two decades is 107.7Kcal/cm2, and the peak sunshine duration in Guangzhou is about 3.424h by simple calculation;

⑵ Daily power consumption of load = = 12.2ah

⑶ The total charging current of solar modules required = 1.05×12.2× (3.424×0.85)=5.9A

Here, the design minimum number of days between two consecutive rainy days is 20 days, 1.05 is the comprehensive loss coefficient of the solar cell module system, and 0.85 is the battery charging efficiency.

⑷ The minimum total power of solar modules = 17.2×5.9 = 102W

Selecting standard battery modules with peak output power of 110Wp and single battery module of 55Wp should ensure the normal operation of the streetlight system in most cases of a year.

2.2 Battery Selection

The calculation of battery design capacity is simpler than the peak wattage of solar modules.

According to the above calculation, the daily power consumption of load is 12.2AH. When the battery is full, it can work continuously for 7 rainy days, plus the work of the first night, the battery capacity:

12.2×(7+1) = 97.6 (AH), 2 batteries of 12V100AH can meet the requirements.

2.3 Solar cell module support

2.3.1 Inclination design

In order to receive as much solar radiation as possible during the year, we need to choose the best Angle for the solar cell module.

In recent years, there have been a lot of discussions on the optimal inclination of solar cell modules in some academic journals. This street lamp is used in Guangzhou. According to the design and reference to the relevant literature [1], the inclination Angle of the bracket of the solar cell module is selected as 16O.

2.3.2 Wind resistance design

In solar street lamp system, wind resistance design is an important structural problem. Wind resistance design is mainly divided into two parts, one is the wind resistance design of the battery component bracket, and the other is the wind resistance design of the lamp pole. Below do the analysis respectively according to the above two pieces.

(1) Wind resistance design of solar cell module bracket

According to the technical specifications of the battery module manufacturer, the windward pressure of the solar cell module is 2700Pa. If the wind resistance coefficient is selected as 27m/s(equivalent to a category 10 typhoon), the battery assembly can withstand only 365Pa of wind pressure based on non-viscous hydrodynamics. Therefore, the component itself can withstand the wind speed of 27m/s without damage. Therefore, the key consideration in the design is the connection between the battery module bracket and the lamp pole.

In the design of the street lamp system, the connection between the battery module bracket and the lamp pole is fixed and connected by bolt rod.