Analysis of Transient Stability in Synchronous Generator Using Nyquist Method

Abstract

There are two factors that must be considered for the power quality analysis of an electrical power system, i.e. frequency and voltage stability. The system that can return to the initial condition or the steady state after a disturbance occurred indicates that the system is stable. This paper aims to detect the transient stability of three generators, which have identical specification of 2.25 MW 6.6 kV and are operated in parallel, based on the frequency performance. In this paper, the stability analysis is determined by using the nyquist method, where the system stability is indicated by the value of the response curve of the system. The analysis results show that the system of three paralleled generators have the value that far from 1 + j0 and the phase margin value and gain margin tend to be minimum. These values indicate that the system is unstable. The system slowly changes into more unstable because the oscillations are getting bigger until the final state. So, it is necessary to change the parameters of each generator that can affect the system stability during synchronization state.

A Comparative Study of Static VAR Systems for ImprovingVoltage Stability in Expansion of Mining Projects with Gearless Motor Drives

“…Large motor's transient stability is defned as the ability to return to its normal state when a fault occurs, depending mainly on the initial state and the severity of the disturbance [48]. During a fault, electrical power is reduced suddenly while mechanical power remains constant, thereby accelerating the rotor.…”

Analisis Pengaruh Static Synchronous Series Compensator Terhadap Kestabilan Transien Menggunakan Metode Nyquist (Analysis of the Static Synchronous Series Compensator’s Effect on Transient Stability Using the Nyquist Method)

“…Mengacu pada penelitian sebelumnya [3], respons osilasi yang semakin buruk akibat gangguan yang terjadi di awal menyebabkan sistem terpecah dan tidak stabil, sehingga beberapa daerah terputus dengan hilangnya suplai daya ke sejumlah konsumennya yang menyebabkan frekuensi menurun. Dilihat dari osilasi respons yang meningkat akibat gangguan besar atau akibat hilangnya sinkronisasi, pada akhirnya dapat mengakibatkan osilasi semakin buruk dan sistem collapse [11].…”

“…Studi stabilitas transien melibatkan gangguan besar, yaitu hilangnya sinkronisasi antar pembangkit (generator). Oleh karena itu, perlu dilakukan pemodelan generator [3]. Penelitian tersebut menyatakan bahwa analisis kestabilan transien menggunakan diagram Nyquist menunjukkan sistem tidak stabil.…”