Power Flow and Protection Analysis of 20kV System as Zero Down Time Program Support in Semarang City Area

Department of Electrical Engineering, Faculty of Engineering, Diponegoro University, Semarang, Indonesia

^* Corresponding author: jakawindarta@lecturer.undip.ac.id

Abstract

The electricity supply reliability is very important to improve electricity supply quality to consumers. Customers in Simpang Lima area, which located in the heart of the city, expect PLN to improve electricity supply reliability around Simpang Lima area, considering that Simpang Lima is known as culinary and business center in Semarang. However, sometimes blackouts occur during busy time which cause losses. Therefore, this study was conducted on the factors that cause blackouts and the solutions used to overcome these problems. Also, this study is conducted to improve electricity supply reliability in the Simpang Lima area and to reduce ENS. Currently, Simpang Lima area is still using the spindle system with medium voltage grid. Consequently, this system will be changed to a Closed Loop system. On the other hand, there are many buildings that use huge electricity load. For instance, Departemen Industri dan Perdangangan, Bank Indonesia, Telkomsel Semarang, DPRD, and Polda Jawa Tengah buildings. These buildings possess loads between 300-400 Amperes. Thus, the electrical supply is only generated from Simpang Lima substation. There will be further problem if blackout occurs in this substation. To avoid unexpected blackouts, this area will be set with the Zero Down Time concept. Zero Down Time is the concept of a power grid that will never goes out. Later, the Simpang Lima area that still uses the Spindle medium voltage grid will be changed to a Closed Loop with medium voltage grid system. Furthermore, this area will be supplied from Simpang Lima substation and the Kalisari substation.