一种新型原边反馈反激式数字控制LED驱动电源设计∗

摘要

设计了一种采用新型数字控制方法的原边反馈反激式LED恒流驱动电源。该电源电路运用拐点检测法测量副边电路放电时间,运用增量式PID算法调节恒流和功率因数,实现对电路的精确恒流控制和保持较高的功率因数。通过分析其控制原理,给出设计流程,最终基于FPGA实现控制,进行了样机设计和算法验证。实验结果表明所提出电路全工作范围内恒流精度达到6%,功率因数高于0.97,整机效率超过80%。本电路结构简单,控制精度高,具有较高的实用价值。%A new primary side feedback flyback digital control LED driver is presented, using corner detection to measure the discharge time of secondary circuit and achieving accurate constant output current and high power factor by increment PID. Through analysis with the control principal,the detailed design process is provided and the control based on FPGA is finally realized. The design of the prototype machine and the verification of algorithm are also carried out. The experiment results show that the accuracy of constant current has reached 6% and power factor correction exceeds 0.97 and the efficiency is up to 80%. The circuit is simple and has high control precision. It is of highly practical value.