一种单级串联型N路输出电流独立控制LED驱动电源

在多彩LED环境照明、LED投影等应用场合,多路输出电流需要实现独立控制。针对此应用目标,提出一种单级串联型N路输出电流独立控制的LED驱动电源,单级结构保证自动实现功率因数校正功能,N-1个由开关管、二极管和输出滤波电容组成的有源输出单元AOU(active output unit)和1个仅由二极管和输出滤波电容组成的无源输出单元POU(passive output unit)串联构成串联型N路输出结构,通过对N路输出电流采样并进行闭环控制,保证各开关管工作占空比不同,即可实现N路输出电流独立控制。以3路输出为例,详细分析了驱动电源的工作原理及其闭环系统控制方法,并搭建了1台总输出功率为120 W的实验样机,实验结果验证了理论分析的正确性。

基于独立相电流控制的PET单级统一控制系统研究

电力电子变压器(PET)的控制系统结构通常采用dq解耦控制,当电网电压不对称时,不能自适应满足系统稳定运行,需加入复杂的辅助控制策略。提出一种独立相电流控制策略,使得不论交流系统对称与否,均能自适应保证PET系统三相间以及各子模块电容电压的稳定控制。该控制策略结合谐振变换器(CLLC型)的电压钳位特性,在保持供电可靠性的同时,简化了传统2级控制,实现单级统一控制。同时详细分析了在不对称交流电网下基于所提出控制策略的PET交流侧输入电流、电压及功率特性。基于PSCAD/EMTDC建立10 kV的PET系统仿真模型,在对称、不对称交流电网下进行功率控制和直流电压支持仿真实验,仿真结果验证了所提出的独立相电流控制策略的正确性、有效性。

Control of Grid Side Converter under Unbalance Voltage Conditions for Variable Speed Wind Turbine

This paper proposes the control of a grid side converter under unbalance voltage conditions for wind turbine system. The control technique is designed to operate under unbalance voltage by independent control between positive and negative components. The converter will regulate the DC link voltage at the specific value （650 V）. To verify an operation of the proposed control, the simulation is conducted by MATLAB/SIMULINK program. The experiments are conducted on a 5 kW system composed of wind turbine simulator, machine side converter and the propose grid side converter for operation under unbalance voltage. By comparing the simulation experimentation results, it can be shown that the proposed control can be continuously operating through an extremely sag voltage without damage. Moreover the proposed control can deliver power to the grid and regulate DC link voltage under unbalance voltage.