Design of strong isolation power supply for Restraining Transient Interference

With the rapid construction and development of smart grid and ultra-high voltage transmission and transformation projects, the transient ground potential rise caused by the operation of switch equipment has a serious impact on the safe operation of local protection devices and various intelligent secondary equipment. When the intelligent substation generates transient ground potential rise due to switching operation, it is possible to make the equipment fail due to strong electromagnetic interference, especially the power supply stability of the secondary side equipment affected. Because the power supply module of the electronic transformer fails under the strong transient electromagnetic interference, false alarm will be generated, resulting in switch misoperation, and affecting the normal operation of the substation. In this paper, an strong isolated power supply is designed, which has the function of suppressing strong transient electromagnetic interference and ensures the stability of power supply for secondary equipment. The circuit hardware design, PCB design, circuit simulation and test are carried out around the strong isolation power supply. Then use Multisim software to simulate the circuit and verify the parameters of the selected device; Finally, the strong isolation power supply is tested. When 1K load is applied, the output voltage is 12V and the current is 0.011mA.