标签：solar energy led lighting

solar energy led lighting and ppfc design

The development of high-power LED lighting solutions manufacturer currently experiencing the biggest design challenge is the thermal design and thermal overload protection, they must overcome ‘s LED lights source is sensitive to heat problems, and will cause excessive heat or improper application of the performance of the LED light source be discounted.

solar energy led lighting and ppfc design

Theory and practice has proven that LED performance and life expectancy is closely related to the PN junction temperature of the LED. When the LED chip junction temperature rise of 10 ° C, the luminous flux will decay to 1%, 50% reduction in the life of the LED, overcurrent, overvoltage and overheating will significantly reduce the performance and service life of the LED street light. Therefore, in addition to good thermal design, safe and reliable overheating protection must be considered.

Usually on the LED, about 20% of the input power is converted to light, 80% is converted to heat. This depends on many factors, fever may be related to the underlying irregular and phonon emission, seal materials. 90% of the total heat generated by the LED, by conduction transmission. Dissipation of heat from the LED junction, conduction is the thermal conductivity of the main channel, convection and radiation is only about 10% of all heat transfer.

Obviously, LED light source requires accurate power and thermal management systems, as compared with other light sources to provide electricity to the LED most of the conversion to heat. Without proper thermal management, heat will affect the LED life and color output. The same time, due to the LED driver devices are silicon devices, they will soon fail. This must be equipped with fail-safe backup overcurrent protection devices.

So why the success of high-power LED lighting design can not be separated from PPTC? Many people think that the LED driver can provide overcurrent and overtemperature protection is not necessary to add a PPTC device in the external, because it would add additional cost. But this is wrong, many of the LED driver is easy to be damaged due to DC voltage and polarity errors. LED driver outputs will damaged or destroyed due to short circuit. Although most LED drivers contain built-in security features include thermal shutdown, open LED and short circuit detection. However, to protect the integrated circuit (IC) and other sensitive electronic components, and may require additional overcurrent protective device. Therefore, only the PPTC (especially resettable PolySwitch PPTC) is to prevent overheating damage to the most appropriate solutions in the high-power LED down lights.

To illustrate this problem, we first look at a typical LED driver to provide what protection function. The most high-power LED constant current drive to provide the typical protection features include: thermal shutdown protection, overvoltage / overcurrent comparator, high-current MOSFET, the current size of the adjustment, a certain level of ESD protection. However, the thermal shutdown feature is just a self-protection function, it is difficult to be applied to the LED overheat designed to protect. Overvoltage / overcurrent protection characteristics of the need for external overvoltage protection circuit, turn off the power may cause other problems. High-current MOSFET failure modes are usually short-circuit, which is potentially unsafe factors. LED dimming with the current regulation characteristics may cause the LED over-temperature.

But the concept of the the PPTC the protection of high-power LED is different, it has the following four unique advantages:

1) failure mode is a high-impedance, even in the fault state, LED is safe.

2) PPTC can directly measure the temperature of the LED, so you can close protection.

3) PPTC can be achieved over temperature, overcurrent and overvoltage protection. Very easy to use, does not require an external circuit. LED, even in protected state can work.

4) allows designers to lower cost, dimming design, without worrying about security issues. Therefore outside of the LED driver with a PPTC device can achieve stronger security, and meet the most stringent safety standards and to achieve cost reduction.

Japanese LED lighting development accelerated

Japan is the earliest country to announce banning the incandescent lamp, and also is the fasteat growing region in solar energy led lighting. In particular, the 3 • 11 large earthquakes and nuclear power plant crisis as a powerful catalyst, along with  the Fukushima nuclear disaster from power saving measures. Energy conservation in Japan is like a strong wind came in,  in 2011, Japan’s penetration rate of LED lighting upgrades significantly. Japan has become one of the world’s hottest LED high bay lighting market.

Throughout the LED lighting market in Japan, not only from the government subsidies and incentives, such as chip giant, Panasonic, Toshiba etc international companies that are very acceptable to LED products. These factors prompt the Japanese solar energy led lighting market which is maturing. With the rapid development of LED lighting industry, the huge opportunities in Japan market become the focus in LED industry. How to grasp the needs and to fully prepared for the LED Street Light market, how to talent showing itself on this opportunities are become the curiosity projects. The sense of quality is Japan market is strong, so it is not easy to enter into Japan market, but after the Japan’s market is mature, it is more difficult to break into. one business manager who are proposing developing Japan’s market said that. ” On this period, our worker are overtime production. It is surprised that the needs of Japan’s market is huge as it just open in the first of this year. We can see that the lighting market in Japan are changing.” Another LED enterprise manager told us who are rush to finish an order told to reporter.

Japanese LED lighting development accelerated

It is well known that in the Asian’s solar energy led lighting market, the first argument by Japanese market is quite common. While Japan 3 • 11 large earthquakes is undoubtedly an large force to accelerate LED lighting market in Japan. Under the influence by lacking of electricity, the development in LED lighting market seems out of people’s expectation. Today’s Japan, it is more urgent to saving energy and improving the utilization of renewable energy. The former bright lights of the “prosperity” scene is no longer.

The rapid improvement of the efficiency of solar energy LED lighting is not only the seeds, but grace also

The rapid improvement of the efficiency of solar energy led lighting and led street light is not only the seeds but also grace

US government regulate to ban 100W incandescent compact fluorescent lamps in 2012. But people want to know that the only reasons for using compact fluorescent. Consumers do not completely change.

In fact, because of all kinds of reasons, a large percentage of consumers have rejected the compact fluorescent lamps, these reasons include flashing lights, color rendering, reliability and cost comparison, the slow start. The small fluorescent light on these issues have been resolved, but in the eyes of many consumers , small fluorescent light is not they wanted. The short term, if  used 100W incandescent lamps are burned, many of these consumers will switch to the halogen incandescent lamp.

This will pose a problem: solar energy led lighting can enter the neutral and the consumer will choose the options? So far, there is no commercially available LED lamps to replace the 100W A19 incandescent. The reason is that the passive cooling 1500lm(100W typical lighting the lamp output) LED is still not on the output in the physical level.

The white LED is a very efficient light source, about one-third of the input power is converted to light, the remaining two-thirds of the power is converted to LED in the heat. So 100lm / W, or about 100W power must be continuous and quickly consumed. If the heat has not been removed, the LED lamp will quickly heat up to 120 ℃ of the maximum working temperature.

This problem may eventually be resolved through the LED luminous efficiency. Last year, the best of cool white LED obtained the lighting efficiency of 100lm / W. This year, a lots of white solar energy led lighting get the efficiency of 120 ~ 130lm / W range. This trend in the foreseeable future will not be decayed.

With the improvement of LED high bay conversion efficiency, the thermal management of improvement is about the square of the efficiency. Because the total power of LED power supply is decreased and the percentage of heat generated by the input power also reduce the number of the corresponding.

 

Japan solar energy led lighting Standard Focuses on Safety and Performance and Aim at the Replacement of Traditional Lighting

Japan is the country in Aisa to gain the most significant result from the implement of solar energy led lighting. Especially after the 311 earthquake, with the increasing consciousness energy-saving, the proportion of bulb LED street light sales rocketed and is the first time to surpass incandescent bulbs in June 2011, to become the highest proportion of electric ball lighting on Japan market.

Beside energy-saving awareness-raising, the remarkable achievement of promoting LED lighting in Japan, is also credited to the related specifications on safety, performance and interchangeability, formulated by body corporate led by the power ball industry of Japan, which not only offers norms for manufacturers to follow but also enable consumers to buy peace of mind.

The current solar energy led lighting standards in Japan are classified into two categories, Japan Industrial Standard and the JEL Japanese electric ball industry specifications. Until July 2011, Japan has already developed 6 JIS LED lighting specifications, and one of them is about safety specifications and performance requirements of LED lighting module and bulb LED light but there is still no national standards on the LED road lighting currently, only local governments to formulate their own specifications requirements.

It was four LED lighting specifications that are developed by the electric ball industry in Japan, mainly to define the ways of LED lighting and LED Tubes marking, and the light mouths between LED lighting and traditional lighting, as well as system compatibility, etc. Unlike traditional lighting LED lighting in the weight, circuit, system requirements. If the compatibility specifications was not developed, it could easily lead to damage of the LED lights when in use, even heat, fire, and other danger.

Referring to international standard IEC, Japanese solar energy led lighting standards are developed to regular safety and color rendition, brightness, life under a variety of environments, to eliminate products whose safety and performance are below the standards, so as to replace traditional incandescent light bulbs and other lighting completely.