高充电效率的恒流太阳能路灯控制器

Solar street lamp controller of high charging efficiency and constant current

针对传统太阳能路灯控制器主要存在充电效率低、恒流精度低的问题,提出基于多路脉冲宽度调制（PWM）恒流技术的新型太阳能路灯控制器的设计方案。该控制器采用复合式DC-DC变换器,通过控制多路PWM信号,实现高效地充放电功能。充电过程以改进的扰动观察法实现最大功率点跟踪（MPPT）,提高充电效率;放电过程通过实时检测LED路灯的实际电流,动态调整相应PWM信号的占空比实现高精度恒流驱动LED路灯。实物测试结果表明该控制器能有效地改善充电效率和恒流源精度,充电速度提高了4%~7%,恒流源精度高达2.5%。

The traditional solar street lamp controller is constrained with the low charging efficiency and the low precision of the constant current source.A novel solar street lamp controller based on the multi-channel PWM constant current technology is designed.A composite DC-DC converter is adopted to realize charging and discharging efficiently through controlling multi-channel PWM signals.During the charging stage,the efficiency of charging is improved by tracking the maximum power point with the perturbation and observation method.During the discharging stage,the duty cycle of the relevant PWM signals are used to implement the high precision constant current source for driving the LED street lamp,which can be adjusted automatically through real-time detecting of the lamp＇s actual current.The test results show that the charging efficiency of the street lamp controller can be improved evidently,and the charging speed increases 4%to 7%.Furthermore,the precision of the constant current source reaches a high level of 2.5%.