LED drive power of the power factor above 95% soon
With advances in technology, lighting, tools and methods are constantly changing, users are presented for the lighting illuminance, uniformity, color rendering and energy efficiency standards higher and higher demand, at this stage, the most eye-catching lighting rising star When none other than non-LED lighting. Light bulbs and fluorescent tubes to replace, embedded lights, street lights and parking lights, working lights (lamps, cupboard lighting), landscape lighting, billboards text circuit, building lighting, and other general lighting market, for example, by 2012, LED lighting market will grow to $ 1,308,000,000, the annual compound growth rate of 17.4%. Therefore, LED general lighting has become a hot market.
However, application of LED lighting market, there are still some problems, including LED consistency, life testing, especially power supply and drive system specifications and other issues remain to be resolved and so on. In the LED drive power requirements, including high efficiency, high power factor, high current control accuracy, high reliability, security isolation, meet EMI standards, small size and low cost. It is noteworthy that the latest Energy Star standards that are greater than 5W of LED lighting products require power factor indicators (PFC) must be greater than 0.7, so that it can achieve further energy saving.
Different power input system requirements
LED lamps cost structure analysis, thermal component accounts for about three into the power supply system into account for the two assembled parts accounted for 5%, LED components accounted for the largest share, amounting to as much as 45%. LED lamps in various parts of the power supply module responsible for energy-saving task. LED lighting currently on the market power input system can be divided into two categories, one for the AC power input front-end back-end system with constant current control module, such products including freezer lights, indoor lighting, lamps, table lamps, MR16 , AR111 and so on. The other for the AC power system integration directly into AC / DC converter and constant current circuit, such products including E27 and GU10-based LED lamps and other light bulbs, PAR lamps, T5 and T8 LED lamp and so on.
According to Kay Ho Shao Jia Yu, said senior manager technology, first select the front-end power supply design in addition to better efficiency and a constant voltage power supply, the back-end supply constant power control module is used according to their product features better power efficiency design. The advantages of front-end AC / DC power supplies, such as switching power supplies, DC adapter, and a constant voltage power supply, optional high and more than a safety certification program designed to reduce the threshold.
Second power supply design is the integration of AC / DC circuit and constant current circuit, the major difficulty exists in the power factor, power efficiency and safety and other considerations, the design, there are some difficulties. For this, the industry says, different power AC - DC (AC-DC) LED lighting applications are suitable for different power topologies. If less than 80 W in power applications, the flyback topology is the standard choice; and in particular about the application of high performance, resonant half-bridge inductor double and single capacitor (HB LLC) is preferred.
High power conversion efficiency in pursuit of objectives
It is understood that the LED lighting, high efficiency topology popular in recent years, the industry can expect mainly in the relatively low power levels (<50W) offers more than 90% performance, while the need for such a high performance reached a new topology, such as a resonant half-bridge topology to replace flyback topology, and so can take advantage of zero voltage switching (ZVS) of the edge.
Power level from the application point of view, AC-DC power supply LED general lighting applications including low power, medium power and high power, such as different types. Low-power applications, power range is usually between 1 to 12W; medium power range covers 8 to 40W; high-power applications, power often than 40W. Overall, LED lighting drive power industry is the major challenge facing the LED drive higher conversion efficiency should be challenging, especially in high-power LED driver is especially true, because all is not as light output power is dissipated as heat , low power conversion efficiency, energy saving LED will affect play.
(Editor：admin) |