As high-power LEDs are commonly used in lighting decoration and lighting, power LED drivers are becoming more and more important. It is possible to use high-power LED lighting for road lighting. Road lighting is the longest used and most power-consuming lamp. The use of LED lights in street lamps will greatly reduce the city's power shortage and save the national energy.
Since the street lamps are all horizontally inserted, LEDs can only be used to make one-sided illumination, but only need to adjust the position when the bulb is installed, and the illumination effect is not affected. The power of the street lamp is divided into 20W, 30W, 40W, 50W with high-power LED, long service life and maintenance-free. Since the LED consumes less power, has a lower voltage, and has a smaller current, the cross section of the installed cable is correspondingly reduced, thereby saving installation costs.
A complete road lighting system consists of a light source, a cable, and a power supply system.
First, the comparison of LED street lights and traditional street lights
Suppose a city has three sections with a length of 3 km, 5 km, and 10 km. The street lamps are laid every 30 meters, and the total number of street lamps required for each of the three sections is 202盏, 333盏. 666盏, the traditional street lamp is based on the high-pressure sodium lamp with a power of 250W, and the LED street lamp is based on the power of 50W.
The price of traditional street lamps is 1000 yuan/盏, and the price of LED street lamps is 3000/盏. The cost of light for roads with three lengths of traditional street lamps is 202*1000=202000 yuan, 333*1000=333000 yuan, 666*1000. =666000 yuan, the cost of light source for laying three kinds of roads with LED street lights is: 202*3000=606000, 333*3000=999000, 666*2000=1998000 (as shown in Table 1)
Second, the comparison of the cost of LED street light and traditional street light cable
Let us analyze the cost of laying cables for two types of roads with three lengths of roads. The load flow of 3 km road traditional street lamp main line cable I=P/U=202*250/220=230A, which requires a copper core with a cross-sectional area of 60 mm2. Cable, its unit price is 120 yuan / meter, then its cable cost is 120 * 3000 = 360,000 yuan, LED street light trunk cable load flow 1 = P / U = 202 * 50 / 220 = 44A, it needs a cross-sectional area of 10mm2 Copper core cable, which requires a copper core cable with a cross section of 12mm2, the unit price is 12 yuan / meter, the cable cost is 12 * 3000 = 36,000 yuan, 5 km road traditional street lamp main line cable load flow I = P / U = 333*250/220=377A, it requires a copper core cable with a cross section of 90mm2, the unit price is 180 yuan / meter, the cable cost is 980 * 5000 = 900,000 yuan, LED street light trunk cable load flow I = P / U = 333*50/220=73A, it requires a copper core cable with a cross section of 20mm2, the unit price is 25 yuan / piece, the cable cost is 25 * 5000 = 125,000 yuan, 10 km road traditional street lamp main line cable flow I = P / U=666*250/220=680A, it requires a copper core cable with a cross section of 400mm2, the unit price is 360 yuan / meter, the cable cost is 360 * 10000 = 3.6 million yuan, LED street light trunk cable load flow I = P / U=666*50 /220=146A, it needs a cross section of 42mm2 copper core cable, the unit price is 60 yuan / meter, the cost is 600,000 yuan, the comparison situation (such as Table 2)
Third, the power supply system
Traditional street lights require a large power supply system. Power type large transformers are very expensive. Moreover, the traditional lamp voltage should not fluctuate too much, otherwise it will seriously affect the life of the lamp. The drive module for LED street lights does not require a large transformer. When the voltage fluctuates, the brightness of the LED street light does not change. The T220C350W12S12 can drive 12W LEDs. When the voltage changes from 180V to 260V, the entire driver can achieve constant current drive. Guaranteed brightness of high-power LED street lights. In addition, the drive has many protection features, the reliability of the entire grid under abnormal conditions.
Fourth, LED street light and traditional street light energy saving
Let's calculate the cost of electricity for one year in the case of three-segment roads with two lengths of light. The calculation method is to light up for 10 hours per day, and the power is calculated at 1 yuan per kWh. The annual electricity consumption of a traditional street lamp of 3 kilometers is 202 (盏)*10 (hours)*365 (days)*250W=184325000w, that is, 184325 kWh, 184,325 yuan. The total annual power consumption of LED street lamps is 202*50*10*365=36865000W, which is 36865 kWh, RMB 36,865; the total annual electricity consumption of 5 km traditional street lamps is 333*250*10*365=303862500W, ie 303,863 kWh, RMB 303,863. The total power consumption of LED street lamps is 333*50*10*365=60772500W, which is 60773 kWh. The total annual electricity consumption of 10 km road traditional street lamps is 666*250*365*10=607725000W, which is 607725 degrees. Electricity, RMB 607,725. The total power consumption of LED street lamps for one year is: 666*50*365*10=121545000W, which is 121,545 kWh, RMB121,545. Comparison situation (as shown in Table 3):
Fifth, LED street light and traditional street lamp life comparison
The street light source circulating in the market today: high-pressure sodium lamp, domestically produced due to quality and technical problems, short life, generally less than 3000 hours, the best imported Philips to 3000-4000 hours, the life of single LED is more than 80,000 hours After the cluster becomes a super-power LED, its life span is more than 60,000 hours, which is equal to 15 times the life of the best high-pressure sodium lamp in circulation. That is to say, the high-pressure sodium lamp is replaced more than 15 times, and the LED street lamp is only Replacement once, the cost of replacing the light source is not living, the maintenance cost and the inconvenience caused by it are the most obvious contrast. (Because the street lamp is special in use, it is difficult to replace, it takes a certain amount of manpower. The machine resources can complete the operation).
to sum up:
Comparing the above three charts with the comparison of life and life, it can be seen that the LED street lamp replaces the traditional street lamp in the cost of the light source is not dominant, but in the laying cost, the LED street lamp can save the cost of the light source, and the electricity cost saved after use is the benefit. The benefits and disadvantages of their respective lifespans, the longer the road to be installed, the greater the cost savings. (The above does not include poles, installation, maintenance, etc., the cost of actually installing LED street lights is much lower than the installation. The cost of traditional street lamps).
