Effect of Prime Mover Governor Parameters on Low Frequency Oscillation

2014 ◽  
Vol 1008-1009 ◽  
pp. 493-496
Author(s):  
Sun Cai ◽  
Xiao Wen Deng ◽  
Yong Xin Feng ◽  
Yan Hui Xu ◽  
Cong Ma
Keyword(s):  
Power System ◽  
Low Frequency ◽  
High Derivative ◽  
Hydraulic Turbine ◽  
Coupling Model ◽  
Small Signal Stability ◽  
Frequency Oscillation ◽  
Low Frequency Oscillation ◽  
Signal Stability ◽  
Governing System

The mechanism of power system low frequency oscillation was discussed in this paper. The coupling model between turbine governor system of plant and power system was established in MATLAB. The possibility of power system low frequency oscillation induced by unit-grid coupling was researched in detail. The simulation results indicate that power system low frequency oscillation will occur under disturbance, if a high derivative gain is used in PID controllers of hydraulic turbine governing system and partial derivative of turbine power output with respect to head varies with load. As for steam turbine, the PID parameters of governor system have important effect on small-signal stability of power system when the damp of power system is not very strong. The power oscillations caused by disturbance is decreased with the use of PID controller in governing system, whereas power oscillation is increased with the use of PI controller.

The Impact of Hydro-Turbine and its Governor System on Power System Low Frequency Oscillation

2012 ◽  
Vol 614-615 ◽  
pp. 875-879
Author(s):  
Jian Guo Zhu
Keyword(s):  
Power System ◽  
Transient Stability ◽  
Mechanical Load ◽  
Low Frequency ◽  
Hydraulic Turbine ◽  
Small Signal Stability ◽  
Frequency Oscillation ◽  
Low Frequency Oscillation ◽  
Hydro Turbine ◽  
The Impact

This paper studies the effect of the soft feedback in hydro-turbine and its governor system on power system transient stability. Low frequency oscillation phenomenon in which the hydraulic turbine sets participate occurred on power system many times this year, which with no mechanism discovered. In this paper, we first study the effect of mechanical load moment output of the prime mover system on the mechanism of low frequency oscillations, then by analysis of small-signal stability on hydro-turbine and its governor system and simulation experiments on an two-generator power system using PSASP, we come to the conclusion that: If the soft feedback output values of hydro-turbine governor systems are set small in the power system, it will come to the unstable oscillation condition.

Modal Research on the Low-Frequency Oscillation of AC/DC System with DFIG-Based Wind Farms

2014 ◽  
Vol 672-674 ◽  
pp. 331-336
Author(s):  
Jing Biao Wang ◽  
Xi Wang Abuduwayiti ◽  
Qin Chao ◽  
Qing Luo
Keyword(s):  
Low Frequency ◽  
Wind Farms ◽  
Small Signal ◽  
Small Signal Stability ◽  
Frequency Oscillation ◽  
Low Frequency Oscillation ◽  
Dc System ◽  
Signal Stability ◽  
Oscillation Modes ◽  
Power Dispatching

Low-frequency oscillation characteristics of AC / DC system with DFIG-based wind farms were studied. Detailed mathematical pure AC and AC / DC system model were established by considering the effects of doubly-fed wind turbine model and DC transmission dynamic model to do small signal stability analysis. The computed results of small signal stability of DFIG-based wind farms integrating pure AC CEPRI36 nodes system or with DC transmission that operated in four connection modes including bipolar neutral grounding at both ends mode, monopole ground return mode, monopole metallic return mode , monopole and two parallel conductor mode with earth return were investigated by using modal analysis method. Then, the characteristics of local oscillation modes and inter-area oscillation modes were respectively analyzed under the two operation modes of the wind farm participating active power dispatching and reactive power dispatching and consequently some new conclusions were drawn.

scholarly journals Probabilistic small-signal stability analysis of power system with solar farm integration

2019 ◽  
pp. 1276-1289 ◽  
Author(s):  
SAMUNDRA GURUNG ◽  
SUMATE NAETILADDANON ◽  
ANAWACH SANGSWANG
Keyword(s):  
Power System ◽  
Density Function ◽  
Forecast Error ◽  
Low Frequency ◽  
Test System ◽  
System Stability ◽  
Small Signal ◽  
Small Signal Stability ◽  
Oscillatory Dynamics ◽  
Signal Stability

Currently, large-scale solar farms are being rapidly integrated in electrical grids all over the world. However, the photovoltaic (PV) output power is highly intermittent in nature and can also be correlated with other solar farms located at different places. Moreover, the increasing PV penetration also results in large solar forecast error and its impact on power system stability should be estimated. The effects of these quantities on small-signal stability are difficult to quantify using deterministic techniques but can be conveniently estimated using probabilistic methods. For this purpose, the authors have developed a method of probabilistic analysis based on combined cumulant and Gram– Charlier expansion technique. The output from the proposed method provides the probability density function and cumulative density function of the real part of the critical eigenvalue, from which information concerning the stability of low-frequency oscillatory dynamics can be inferred. The proposed method gives accurate results in less computation time compared to conventional techniques. The test system is a large modified IEEE 16-machine, 68-bus system, which is a benchmark system to study low-frequency oscillatory dynamics in power systems. The results show that the PV power fluctuation has the potential to cause oscillatory instability. Furthermore, the system is more prone to small-signal instability when the PV farms are correlated as well as when large PV forecast error exists.

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