Indonesian Journal of Electrical Engineering and Computer Science Vol. 24, No. 3, December 2021, pp. 1278~1287 ISSN: 2502-4752, DOI: 10.11591/ijeecs.v24.i3.pp1278-1287  1278 Journal homepage: http://ijeecs.iaescore.com Impact of micro hydro power plants on transient stability for the micro grid 20 kV system Syarifuddin Nojeng 1 , Syamsir 2 , Reny Murniati 3 1,2 Department of Electrical Engineering, Universitas Muslim Indonesia, Makassar, Indonesia 3 Department of Electrical Engineering, Universitas Sawerigading, Makassar, Indonesia Article Info ABSTRACT Article history: Received Oct 1, 2020 Revised Oct 29, 2021 Accepted Nov 6, 2021 Transient stability analysis is conducted to determine the ability of the electric power system in maintaining the operating stability after a major disturbance. The disturbance can be trigger an impact on the stability of the rotor angle, voltage, and system frequency which can cause loss of synchronization. In this paper, the impact of the interconnection of the Tombolo-Pao mini hydro power plant (MHPP) on the stability of the system was analyzed by several scenarios to determine the behavior of system parameters in a 20 kV system interconnection network. This research is an implementation of regulatory provisions relating to the study of the connection to the PLN distribution network through by regulator. Based on the result of simulation study, transient stability of generators at Tombolo- Pao power plant about 0.1 second, will not occur with network configuration according to modeling activation of anti-islanding protection of Tombolo Pao Power Plant which is set by 2 second. The simulation results show that the location of the disturbance in the electric power system has been influenced by the behavior of the power plant (synchronous generator) which can lead to the instability of the micro-hydro connected to the micro-grid system 20 kV. Keywords: Distributed generation Micro grid Mini hydro power plant Transient stability This is an open access article under the CC BY-SA license. Corresponding Author: Syarifuddin Nojeng Department of Electrical Engineering Universitas Muslim Indonesia Urip Sumoharjo St. km.05, Makassar, Indonesia Email: syarifuddin.nojeng@umi.ac.id 1. INTRODUCTION Transient stability analysis is carried out to determine the ability of the electric power system to maintain operating stability after a major disturbance. The disturbance can have an impact on the stability of the rotor angle, voltage, and system frequency which can cause loss of synchronization. The stability condition is the validity of the conditions for connecting the generator to PLN's distribution network, which is the Regulation of the Minister of Energy and Mineral Resources NO. 12/ESDM/2014 concerning purchase of electricity energy from hydropower plants to the State of Electricity Company (PT. PLN) and provisions of the board of directors of PT. PLN through the Regulation No.0357.K /DIR/2014, concerning guidelines for connecting renewable energy power plants to distribution systems PLN [1]. It is a challenge for electricity providers to always provide a reliable and sustainable electricity supply by building renewable plants that can improve the appearance of the system [2]. Transient stability analysis is carried out to determine the ability of the electrical power system to maintain the initial stability of operation after a major disturbance that can have an impact on the stability of the rotor angle, voltage, and the system frequency which can cause the loss of synchronization, and in the worst conditions, it can cause the black-out system. The stability problems