高能源效率、高可靠性HB-LED驱动电源关键技术研究

Worldwide, more than 20% of all electric power is consumed by residential, commercial or industrial lighting. Due to the potential of high efficacy, good optical performance, long lifetime, environmental friendliness, and compact size over the conventional lighting devices, high-brightness light-emitting-diodes (HB-LEDs) have emerged as a promising lighting technology to replace the energy inefficiency incandescent lamps and mercury-based fluorescent lamps. However, power supplies for HB-LED lighting application have many drawbacks: low efficiency, short lifetime, and poor lighting quality like flicker, which have become the bottleneck for the development of HB-LED lighting. After following the Twin-Bus HB-LED drivers, the efficiency problem under the entire load rang, specifically the efficiency at light load, is firstly addressed in order to maximize the lighting’s potential of energy saving. Thus, the hybrid-mode control with multiple operation modes and improved burst mode control methods with optimized pulse width are studied in this proposal. On the other hand, to achieve the high reliability, the electrolytic capacitors with short lifetime have to be avoided in the HB-LED power supply. However, the conventional methods for eliminating electrolytic capacitors resulted in distorted input current, reduced efficiency, and poor lighting quality. Therefore, in this proposal, two novel control methods with high rejection capability of double line frequency voltage ripple, Proportional Integral cascaded Qusi-Resonant (PI-QR) and Proportional Integral cascaded Qusi-Notch Filter (PI-QNF) are proposed firstly. The proposed solutions provide significant double line voltage reduction while it has negligible impact on the phase and gain margins of the control loop gain. Compared with its counterpart, it has no additional cost, efficiency, and complexity penalties. Furthermore, the high efficiency PWM converter incorporating resonant conversion mode and the driver approach considering light attenuation compensation and temperature compensation are also discussed in this proposal. Finally, the validity and effectiveness of the proposed solutions are verified by the experiment results from the prototype.

照明用电约占人类总用电的20%以上，是节能的关键。HB-LED因其高光效、长寿命、环保等优点，成为21世纪最具潜力的绿色光源。然而其驱动电源却因效率不高(特别是轻载效率)、寿命较短、驱动方式不佳等问题，成为HB-LED 照明发展的瓶颈。项目在继前期研究的Twin-Bus HB-LED驱动电源之后，首次从能源利用率的角度，提出调光状态下的效率问题，即驱动电源的能源效率，并提出和研究多模式混合控制及最佳脉冲宽度Burst Mode的控制策略；针对传统电解电容消去方法致使驱动电源效率降低、输入电流畸变及HB-LED光输出闪烁的问题，首次提出具有较强低频纹波抑制能力的PI级联准谐振和PI级联准陷波器的新型控制方法。该方法不但降低了传统PI控制对高控制带宽的要求，而且没有任何惩罚；讨论了嵌入谐振模式的高效率PWM变换器拓扑和考虑光衰及结温补偿的HB-LED驱动技术。最后，构建了原理样机和实验验证。

HB-LED因其高光效、长寿命、环保等优点，成为21世纪最具潜力的绿色光源。然而其驱动电源却因效率不高、寿命较短、驱动方式不佳等问题，成为HB-LED 照明发展的瓶颈。本项目针对HB-LED驱动电源高效率、高性能、长寿命的需求，从电路拓扑、驱动架构和控制方法进行研究，主要研究成果包括： (1) 针对传统三级式架构中的经典电路拓扑，将Boost PFC与半桥LLC进行集成，提出了一种单级无桥Boost-LLC AC-DC变换器拓扑； (2) 以提出的新型单级Boost-LLC AC-DC变换器为基础，结合Twin-Bus架构，提出一种准单级、无电解电容高功率HB-LED照明驱动方案；该方案具有最少的功率转换级数、较高的转换效率、最低的成本和高的可靠性以及较优的输入输出特性；(3)在分析电路机理和相关调制策略的基础上，提出了基于Bus电压前馈和反馈的两种PFM-PWM混合控制技术, 解决了全球输入电压下Bus电压过高及LLC谐振参数设计困难的问题；(4) 引入准谐振技术术和开关管最小关断时间Toff_min 控制，解决了针对传统低频纹波对消架构中前级CRM Flyback 拓扑存在负载范围和线周期内开关管开关频率变化范围较宽，开关损耗大的问题；(5) 提出了一种改进型的无桥SEPIC PFC电路拓扑, 克服了传统无桥SEPIC PFC存在环流噪声的缺点。.研究成果解决了传统HB-LED驱动电源的低效率、高成本、短寿命等问题，促进了HB-LED照明电源的性能提升，对优化相关电源产品性能、降低成本、节能减排具有重要意义。