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

Hydro Turbine ◽

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.

Study of small signal stability using PSAT including DFIG based wind penetration

Journal of Innovations in Engineering Education ◽

10.3126/jiee.v2i1.36667 ◽

2019 ◽

Vol 2 (1) ◽

pp. 137-145

Author(s):

Ram Prasad Pandey

Keyword(s):

Power System ◽

Wind Power ◽

Transient Stability ◽

System Analysis ◽

Low Frequency ◽

Synchronous Generators ◽

Frequency Oscillation ◽

Global Mode ◽

In early days of power engineering, the power system consisting of synchronous generators faced different low frequency oscillation problems and they were solved by different researchers by using suitably AVR and PSS. Later, the electricity industry is turning increasingly to renewable sources of energy to generate electricity. Wind is the fastest growing and the most widely utilized emerging renewable energy technology for power generation at present. With the increasing penetration of wind power in the power system, the impact in power system performance should be fully investigated, particularly for doubly fed induction generation (DFIG) wind turbine since this type of renewable source is gaining prominence in the power system industry. Main purpose of this study is to examine the impacts of wind power integration in the low grid from low frequency oscillation perspective. The benchmarked Two Area System is considered for this analysis using Power System Analysis Toolbox (PSAT). The critical modes of oscillation are selected from eigenvalue analysis and their participation factors are studied to identify their sensitivity. Also the time domain analysis is run in every cases to study the transient stability. From TAS, concept of local and global mode oscillation can be understood clearly. Replacing synchronous generators in TAS by DFIG WTG one by one of same rating gave conclusion that low frequency stability depends on the location of DFIG penetration and operating scenario. The results show that there is both beneficial and detrimental effects due to DFIG WTGs. The installation of PSS in the critical generators greatly enhances the system damping.

Effect of Prime Mover Governor Parameters on Low Frequency Oscillation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1008-1009.493 ◽

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 ◽

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 wind power inverse-peaking characteristics on power system low frequency oscillation

2012 China International Conference on Electricity Distribution ◽

10.1109/ciced.2012.6508635 ◽

2012 ◽

Author(s):

Shaoxiang Feng ◽

Dichen Liu ◽

Xiaoming Yang ◽

Xiaorong Xiang

Keyword(s):

Power System ◽

Wind Power ◽

Low Frequency ◽

Frequency Oscillation ◽

Analysis of Power System Low Frequency Oscillation Considered the Impact of Turbine Power Changing

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.543-547.751 ◽

2014 ◽

Vol 543-547 ◽

pp. 751-756

Author(s):

Pai Liu ◽

Lin Zhang ◽

Long Sheng Hu ◽

Guo Jian Yang ◽

Ye Zhou Hu

Keyword(s):

Power System ◽

Low Frequency ◽

Power Grids ◽

Sustained Oscillation ◽

Frequency Oscillation ◽

Interconnected Power System ◽

Power Oscillation ◽

The Stability ◽

In this paper, the author introduced resonance mechanism into the stability analysis of power system, established comprehensive mathematical model including units and power grids by considering the effects from generation side and line side. On this basis, the author simulated several typical disturbances to analysis by MATLAB SIMULINK. The result showed that the power oscillation will be caused when the natural frequency of the grid and the frequency of disturbances are same or similar, especially in multi-area interconnected power system. The disturbances from different units can produce a significant impact transient or sustained oscillation by superposition, endanger the stability of power system.