The Galaxy 300 Uninterruptible Power Supply Electromagnetic Conduction And Radiation Suppression Design

The electronic equipments are becoming more and more complex. Specially, the mixture of analog signal and digital signal is more popular; the work frequency is higher and higher. These factors cause the disturbance between equipments is much worse. To make sure the working devices don't disturb the others and reduce the electromagnetic pollution, more and more countries force the production to meet EMC standard. The big Uninterruptible Power System (UPS) is the protector of very important location, such as aerodrome, data center…, so its EMC performance is really very important. To improve the efficiency and reduce the pollution to power network, the big UPS often use the convertor with high work frequency, its front part is AC-DC module of Power Factor Correction (PFC) and the rear part i s DC-AC modu I e of the transducer. While UPS has high efficiency and save energy source,it also increase the electromagnetic disturbance.The investigated content is the design of electromagnet i c conduction and radiated emission for Galaxy 300 UPS. Make sure they can meet the EMC standard of UPS,IEC 62040-2.The UPS of Galaxy 300 has a lot of requirements from its market. This article analyzes the limitation of electromagnetic conduction and radiated emission for market requirements. Then with the consideration of project design, meet both the market and EMC requirements.Regarding electromagnetic conduction, this article point out that due to the market requirement and the character of circuit topology, the PFC module is the main disturbance source. To meet the special configuration requirement of market, the fi Iters can't get its best performance. To meet the standard of IEC 62040-2,2 methods are used:one is to reduce the disturbance source in PFC module; the other is to use 3-level LC filters. These methods refer the design of filters and differential mode inductor, the choice of bypass capacitors and Mn-Zn ferrite core, the layout of module configuration and system cable.Regarding to radiated emission, this article also point out the limitation of market requirement and function module. Then by disturbance source and coupling path, reduce the radiated disturbance and meet the standard of IEC 62040-2. There are 2 methods for coupling path:one is using bypass capacitors, Ni-Zn ferrite core and the layout of system cable to reduce the radiated disturbance from the outside cable; the other is to reduce the radiated disturbance from the gap of UPS panel by screen, ground connection and making the disturbance source far away the gap. The part of disturbance source point out that the safe low voltage power supply on control board produce high disturbance and radiate by the gap of display. The method i s to change the rect i fy d i ode on the power supp I y.This article also refers the design of clock circuit on PCB.