Mitigation of low frequency oscillations in power systems based on Mamdani fuzzy inference

2019 ◽  
Vol 41 (12) ◽  
pp. 3477-3489
Author(s):  
Hong-Liang Gao ◽  
Xi-Sheng Zhan ◽  
Yi-Ran Yuan ◽  
Zi-Jie Pan ◽  
Guo-Long Yuan
Keyword(s):  
Power Systems ◽  
Power System ◽  
Control Strategy ◽  
Pid Controller ◽  
Fuzzy Inference ◽  
Low Frequency ◽  
Power System Stability ◽  
System Stability ◽  
Low Frequency Oscillations ◽  
System Stabilizer

Several methods have been proposed and implemented to improve the power system stability. Based on the theory of proportional-integral-derivative (PID) excitation control and the composition principle of fuzzy PID controller, a novel PID controller based on Mamdani fuzzy inference (MFPID) is proposed in this paper. The proposed controller realizes the self-adjustment of the excitation controller parameter. Furthermore, the MFPID and power system stabilizer (PSS) subsection switch control strategy (MFPID-PSS) is presented based on the advantages of PSS and MFPID. In MFPID-PSS strategy, by switching the control strategy between MFPID and PSS at appropriate moment, the MFPID-PSS method acquires the overshoot as small as PSS, and at the same time acquires the adjusting time as short as MFPID. The simulation results demonstrate that the MFPID-PSS method improves the power system stability and has better mitigation effect for low frequency oscillations in power systems after disturbances.

Improvement of Dynamic Electrical Power System Stability Using Riccati Matrix Method

2015 ◽  
Vol 793 ◽  
pp. 29-33 ◽  
Author(s):  
M. Irwanto ◽  
Norfadilah ◽  
N. Gomesh ◽  
M. Irwan ◽  
M.R. Mamat
Keyword(s):  
Power System ◽  
Matrix Method ◽  
Low Frequency ◽  
Power System Stability ◽  
System Stability ◽  
Electrical Power System ◽  
Successful Operation ◽  
Power Utility ◽  
Low Frequency Oscillations ◽  
Riccati Matrix

Power system stability means the ability to develop restoring forces equal to or greater than the disturbing forces to maintain the state of equilibrium. Successful operation of a power system depends largely on providing reliable and uninterrupted service to the loads by the power utility. The stability of the power system is concerned with the behavior of the synchronous machines after they have been disturbed. If the disturbance does not involve any net change in power, the machines should return to their original state. Due to small disturbances, power system experience these poorly damped low frequency oscillations. The dynamic stability of power systems are also affected by these low frequency oscillations. This paper presents to analyze and obtain the optimum gain for damping oscillation in SMIB by using Riccati matrix method to improve dynamic power system stability. The result shows that with suitable gain which is act as a stabilizer that taken from Riccati matrix, the oscillations of rotor speed and rotor angle can be well damped and hence the system stability is enhanced.

scholarly journals Teaching power system stabilizer and proportional-integral-derivative impacts on transient condition in synchronous generator

2021 ◽  
Vol 10 (5) ◽  
pp. 2384-2395
Author(s):  
Sugiarto Kadiman ◽  
Oni Yuliani ◽  
Trie Handayani
Keyword(s):  
Power Systems ◽  
Power System ◽  
Pid Controller ◽  
Synchronous Generator ◽  
System Stability ◽  
Power System Stabilizer ◽  
Transient Condition ◽  
Proportional Integral Derivative ◽  
Proportional Integral ◽  
System Stabilizer

Understanding the concepts based on problem solving is not an easy methodology in teaching the impact of power systems stabilizer (PSS) on transient synchronous generator using MATLAB capability. Experiments conducted in simulating sessions play an important role in this teaching. This simulation can simulate power system stability behavior with reasonable accuracy in less time. This transient phenomenon of a power system utilizing synchronous generator and modelling by fully three-phase model with changes in stator flux linkages neglected is analyzed by employed single machine infinite bus taken to the power system. Whereas a power system stabilizer which consist of a wash-out circuit, two stages of compensation, a filter unit, and a limiter, is applied to control voltage and frequency of power systems in transient condition. Proportional-integral-derivative (PID) controller tuned by Ziegler-Nichols’s method is cascaded to conventional PSS in order to enhance the response time of system while providing a better result in damping for oscillation. This gives the clear idea about PSS and PID controller impacts on transient synchronous generator and its enhancement to the students of electrical engineering program, Institut Teknologi Nasional Yogyakarta.

scholarly journals An Accurate Method for Delay Margin Computation for Power System Stability

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3466 ◽  
Author(s):  
Ashraf Khalil ◽  
Ang Swee Peng
Keyword(s):  
Time Delay ◽  
Power Systems ◽  
Power System ◽  
System Stability ◽  
Area Measurement ◽  
Power System Stabilizer ◽  
Iteration Algorithm ◽  
Measurement Units ◽  
System Stabilizer ◽  
Delay Margin

The application of the phasor measurement units and the wide expansion of the wide area measurement units make the time delay inevitable in power systems. The time delay could result in poor system performance or at worst lead to system instability. Therefore, it is important to determine the maximum time delay margin required for the system stability. In this paper, we present a new method for determining the delay margin in the power system. The method is based on the analysis in the s-domain. The transcendental time delay characteristics equation is transformed to a frequency dependent equation. The spectral radius is used to find the frequencies at which the roots cross the imaginary axis. The crossing frequencies are determined through the sweeping test and the binary iteration algorithm. A single machine infinite bus system equipped with automatic voltage regulator and power system stabilizer is chosen as a case study. The delay margin is calculated for different values of the power system stabilizer (PSS) gain, and it is found that increasing the PSS gain decreases the delay margin. The effectiveness of the proposed method has been proved through comparing it with the most recent published methods. The method shows its merit with less conservativeness and fewer computations.

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