Analisis Setting Waktu Rele Pengaman Di PT. Pupuk Sriwidjaja Dengan Mempertimbangkan Transient Stability Assessment

Pada sistem tenaga listrik, kestabilan transien mempunyai peranan yang sangat penting dalam menjaga keamanan dan keberlangsungan operasinya. Pada saat terjadi gangguan, rele pengaman akan bekerja untuk membuka circuit breakers dalam kurun waktu tertentu. Akan tetapi hal ini tidak menjamin sistem dapat terjaga kestabilannya. Hal ini disebabkan adanya waktu pemutus kritis / critical clearing time (CCT) pada sistem tenaga listrik. CCT adalah perhitungan batas waktu kritis setelah terjadi gangguan dimana saat terjadi gangguan harus diputus sebelum CCT. Apabila gangguan diputus setelah CCT maka sistem tidak dapat terjaga kestabilannya. Dengan metode Time Domain Simulation (TDS) nilai CCT yang didapatkan akurat tetapi hanya berupa nilai batas stabil dan batas tidak stabil sistem tenaga listrik. Pada PT. Pupuk Sriwidjaja saat ini telah mempunyai setting waktu rele pengaman yang belum mempertimbangkan Transien Stability Assessment. Agar perusahaan ini lebih handal dan dapat menjaga kontinuitas kebutuhan produksinya maka harus didapatkan nilai CCT metode TDS. Setelah diperoleh hasil CCT kemudian digunakan untuk pertimbangan setting waktu rele pengaman. Hasil analisa didapatkan bahwa terdapat beberapa bus di PT. Pupuk Sriwidjaja yang setting waktu nya masih diatas nilai CCT. Penambahan peralatan proteksi yang mampu bekerja secara cepat diperlukan, dalam hal ini adalah rele differential yang mampu bekerja 1-3 cycle dalam mengisolir gangguan agar sistem dapat terjaga kestabilannya. ================================================================================ In the electric power system, transient stability has a very important role in maintaining the safety and continuity of operations. In the event of interruption, the safety relay will work to open circuit breakers within a certain time. However, this does not guarantee the system stability can be maintained. This is due to the breaker time critical / critical clearing time (CCT) on the power system. CCT is the calculation of the critical time limit after which the interruption occurs during disturbances must be disconnected before the CCT. If the disorder is disconnected after CCT then the system can not be maintained its stability. With methods Time Domain Simulation (TDS) CCT values obtained are accurate but only in the form of limit values and limit unstable stable power system. At the PT. Fertilizer Sriwidjaja now has a time setting that is not considered a safety relay Transient Stability Assessment. So that the company is more reliable and can maintain the continuity of production needs to be obtained CCT value TDS method. Having obtained the results of CCT is then used for the consideration of setting a safety relay. Results of the analysis showed that there are several buses in PT. Fertilizer Sriwidjaja the time setting is still above the value of the CCT. The addition of protective equipment that is able to work quickly is necessary, in this case the differential relay which is able to work 1-3 cycle disorders in order to isolate the system can be maintained its stability