DAMPING MODEL POWER SYSTEM OSCILLATION
1. Daryanto; 2. Purwanto G; 3. Faris H. Makarim

1 dan 2 = Universitas Negeri Jakarta
3. School of Electrical Engineering and Informatics
Bandung Institute of Technology

Abstract

Daryanto, Purwanto G. dan Faris H. Makarim
Program Studi Pendidikan Teknik Elektro, Fakultas Teknik, Universitas Negeri Jakarta

Todays electrical power system is characterized by the presence of resources and users located far apart and covering a large area, so that the delivery of electrical power to load centers is carried out through a transmission network with a limited capacity. Such operation will cause the steady state to be impaired or will result in poor attenuation of the electromechanical oscillations, and at worst the power system will fail. This study aims to investigate the effect of dynamic load parameters on the oscillation damping of the electric power system.
The behavior of the electric power system after a disturbance at various values of certain dynamic load parameters is shown through a simulation using the Simulink application program from Matlab. The models developed in this study include dynamic load models and synchronous generator models. The dynamic load model is developed from the Hill model which is based on the load power response due to changes in voltage. The mathematical formula describing the interaction between voltage and load power is realized by the first level differential equation. Meanwhile, the electric power system model is based on the model developed by Demello, which is a single engine connected to an infinite bus. The synchronous engine in this model is obtained from the classical Park model to assume (1) a balanced condition, (2) the coil resistance and stator flux derivatives are neglected, (3) the saturation effect is negligible, (4) the transmission network is assumed to have zero resistance, and (5) local loads are assumed to depend only on real power. Based on these two models, an overall block diagram is made that illustrates the interaction between dynamic loads and the electric power system.
The results showed that the addition of dynamic load can reduce the oscillations ∆δ and ∆Vt when there is a disturbance and a decrease in the reference voltage makes ∆δ rise while ∆Vt falls. The closer npt/nps is to 1, the closer the transition values ∆δ and ∆Vt are to the steady state. If npt/nps < 1, the curve ∆δ will oscillate at a value above the steady value and ∆Vt will oscillate at a value below the steady value. Meanwhile, if npt/nps > 1, the curve ∆δ will oscillate at a value below the steady value and ∆Vt will oscillate at a value above the steady value. The conclusion of this research is that the greater the value of nps, the greater the value of ∆δ and the smaller the value of ∆Vt and the greater the value of Tp, the transition of ∆δ and ∆Vt to a steady value will be longer.

Keywords: damping, oscillation, dynamic load parameters, electric power system, synchronous generator.

Topic: Innovations in Engineering and Education