| Title |
Active Control Pulse Variable Technology to Increase the Measurement Range of IMD |
| Authors |
Jong-Yun Jeong ; Sung-Geun Song ; Jung-Hoon Ahn |
| DOI |
https://doi.org/10.6113/TKPE.2024.29.3.176 |
| Keywords |
Energy storage system; Insulation monitoring system; RE100; Renewable energy |
| Abstract |
Recently, in an effort to reduce carbon emissions worldwide, participation in projects such as RE100 has increased internationally and has seen a rise in ESS installation. However, since 2018, fire accidents have increased rapidly, and safety regulations have been strengthened. ESS mainly uses the IT grounding method. IT ground has the advantage of flowing very little accident current because a closed circuit is not configured even if a single-wire grounding occurs, but it has the disadvantage of difficulty in detecting a single-wire grounding accident. Therefore, monitoring insulation resistance has become an important factor for the safety of the system, forcing the installation of IMD. This paper analyzed the principles and shortcomings of the active method mainly used in IMD and subsequently proposed a solution to the problem. Currently, most IMDs use a method of injecting a fixed value of current in the form of a certain pulse between the power line and the ground, and the size of the pulse is regulated by IEC-61557. As a solution to the above problem, a pulse current variable circuit using BJT and MOSFET was proposed. Measurement of insulation resistance improves accuracy and measurement range by proposing an algorithm that changes current depending on size. In addition, simulation and actual circuits were manufactured to verify the improved circuits to confirm their performance. |