Development experience of designing Electronic Devices for substation environment with emphasis on electromagnetic field and interference suppression

Intelligent Electronic Devices (IEDs) offering real time response have become backbone of Modern Substations. Co-existence of conventional Mechanical hardwired systems and Digital electronics with embedded logics as a part of control system, in Medium and High Voltage Substation environment is also now inevitable. Further, designs deploying integrated circuits operating at voltage levels lower than 5 V are further spreading fast and hence designing IEDs for Substation environment poses its own set of challenges. The design and development experience varies with the engineers. However, there are always some experiences which form the bottom line and if shared would be of good help to the other design engineers. The paper presents the author experiences on development of IEDs for such environment with emphasis on Hardware, Software and Product engineering aspects. It also includes some useful tips to be taken at the component layout, grounding, earthing, and PCB design stage. Many other relevant issues to achieve reliable operations against the given EMI ambient of installations have also been touched upon.