LED驱动电路超高次谐波发射机理研究

脉冲宽度调制PWM(pulse width modulation)变频器、开关电源等电力电子设备的规模化接入电网,将向电网注入大量超高次谐波,由此产生的电磁干扰问题势必越发严重.对LED驱动电路超高次谐波发射机理进行了深入研究,首先通过对电流控制模式LED驱动电路建模,求解出了MOSFET任意开关时刻,并建立了谐波源等...

Study on Supraharmonics Emission Mechanism for LED Drive Circuit

PWM converter,switching power supply and other power electronic equipment will inject a large number of Supraharmonics into the grid when they are connected to the grid on a large scale. In this paper, the Supraharmonics emission mechanism of LED driver circuit will be studied in depth. Firstly, by modeling different topologies of constant-current LED drive circuit under switching state, the solution of arbitrary switching time of MOSFET and the establishment of harmonic source equivalent model are completed. Then the influence of Supraharmonics source on the harmonic content of the network side is analyzed when the circuit works in different topologies. The corresponding switching function is obtained, and the expression of the current content of UHG in the network side is solved. Finally, according to the simulation, the influence of the parameters on the Supraharmonics content of the mesh side is verified.