Technical Report No.1343

No. 1343

Evaluation of the Effects of Grounding Systems on Lightning Surges and EMC

Investigating R&D Committee on Evaluation of the Effects of Grounding Systems on Lightning Surges and EMC

Keyword :

EMC, Grounding, Insulation Coordination, Lightning Surges, Overvoltages

The grounding systems are essential to determine the insulation levels, electric preservation levels and EMC levels of electric equipment. Concerning the grounding systems, therefore, their various electrical characteristics ranging from those in a steady state to those in transient conditions and their designing methods have been examined theoretically and experimentally from different viewpoints. However, technical brochures published so far have neither systematically summarized the electrical characteristics and designing methods of the grounding systems from the viewpoint of theories, measurements and designs, nor mentioned how to apply them to the facilities. Meanwhile, with the recent development of ICT (Information and Communication Technologies), both the high voltage electric facilities and the low voltage facilities, such as the low voltage and control circuits and the telecommunication circuits, have come to be used concurrently in electric equipment for common purposes. Therefore, the conventional designing methods of the grounding systems should be reexamined.
Considering such circumstances, this technical report mainly summarized the results obtained from the investigation and examination related to the following three items:
(1) Structure of grounding systems used in the electric power systems (main circuit, low voltage and control circuits, and telecommunication circuits), telecommunication systems, railroad systems, consumer's facilities and renewable energy systems
(2) Electrical characteristics of grounding systems (characteristics in a steady state and transient conditions, and grounding potential rise)
(3) The Role of the grounding systems on the insulation coordination and design of EMC, and their effects, and the design concepts of the grounding systems
We expect that this report will be instrumental in the research related to the grounding systems, and useful for developing and designing the grounding systems.