scholarly journals Application of Neuro-Fuzzy Controller to Replace SMIB and Interconnected Multi-Machine Power System Stabilizers

2020 ◽  
Vol 12 (22) ◽  
pp. 9591 ◽  
Author(s):  
Aliyu Sabo ◽  
Noor Izzri Abdul Wahab ◽  
Mohammad Lutfi Othman ◽  
Mai Zurwatul Ahlam Mohd Jaffar ◽  
Hakan Acikgoz ◽  
...  

In this research, an effective application and performance assessment of the Neuro-Fuzzy Controller (NFC) damping controller is designed to replace a single machine infinite bus (SMIB) power system stabilizer (PSS), and coordinated multi PSSs in large interconnected power systems are presented. The limitation of the conventional PSSs on SMIB and interconnected multi-machine test power systems are exposed and disclosed by the proposed NFC stabilizer. The NFC is a nonlinear robust controller which does not require a mathematical model of the test power system to be controlled, unlike the conventional PSSs’ damping controller. The Proposed NFC is designed to improve the stability of SMIB, an interconnected IEEE 3-machine, 9-bus power system, and an interconnected two-area 10-machine system of 39-bus New England IEEE test power system under multiple operating conditions. The proposed NFC damping controller performance is compared with the conventional PSS damping controller to confirm the capability of the proposed stabilizer and realize an improved system stability enhancement. The conventional PSSs’ design problem is transformed into an optimization problem where an eigenvalue-based objective function is developed and applied to design the SMIB-PSS and the interconnected multi-machine PSSs. The time-domain phasor simulation was done in the SIMULINK domain, and the simulation results show that the transient responses of the system rise time, settling time, peak time, and peak magnitude were all impressively improved by an acceptable amount for all the test system with the proposed NFC stabilizer. Thus, the NFC was able to effectively control the LFOs and produce an enhanced performance compared to the conventional PSS damping controller. Similarly, the result validates the effectiveness of the proposed NFC damping controller for LFO control, which demonstrates more robustness and efficiency than the classical PSS damping controller. Therefore, the application and performance of the NFC has appeared as a promising method and can be considered as a remarkable method for the optimal design damping stabilizer for small and large power systems.

2021 ◽  
Vol 13 (6) ◽  
pp. 3131
Author(s):  
Tawfik Guesmi ◽  
Badr M. Alshammari ◽  
Yasser Almalaq ◽  
Ayoob Alateeq ◽  
Khalid Alqunun

This paper presents a new approach for coordinated design of power system stabilizers (PSSs) and static VAR compensator (SVC)-based controller. For this purpose, the design problem is considered as an optimization problem whose decision variables are the controllers’ parameters. Due to nonlinearities of large, interconnected power systems, methods capable of handling any nonlinearity of power networks are mostly preferable. In this regard, a nonlinear time domain based objective function is used. Then, the coyote optimization algorithm (COA) is employed for solving this optimization problem. In order to ensure the robustness and performance of the proposed controller (COA-PSS&SVC), the objective function is evaluated for various extreme loading conditions and system configurations. To show the contribution of the coordinated controllers on the improvement of the system stability, PSSs and SVC are optimally designed in individual and coordinated manners. Moreover, the effectiveness of the COA-PSS&SVC is assessed through comparison with other controllers. Nonlinear time domain simulation shows the superiority of the proposed controller and its ability in providing efficient damping of electromechanical oscillations.


Author(s):  
Aliyu Sabo ◽  
Noor Izzri Abdul Wahab ◽  
Mohammad Lutfi Othman ◽  
Mai Zurwatul Ahlam Mohd Jaffar ◽  
Hamzeh Beiranvand ◽  
...  

Generally, power systems experience a variety of disturbances that can result in low frequency electromechanical oscillations. These low frequency oscillations (LFOs) take place among the rotors of synchronous generators connected to the power system. These oscillations may sustain and grow to cause system separation if no adequate damping is provided. Power system stabilizers (PSSs) are one of the alternative devices used to solve this rotor oscillation problem. The major limitation of using PSSs at the excitation system of synchronous machine is that the conventional PSS is a permanent parameter type operating under a particular system operating condition, and its parameters are acquired through trial and error. An efficient way of operating the PSS has been by designing the PSS parameters using a powerful optimization procedure. However, designing PSS damping controller is a cumbersome task as it needs a comprehensive test system modeling and a heavy computational burden on the system. In this research, a novel, model-free neuro-fuzzy controller (NFC) is designed as the LFOs’ damping controller to substitute the traditional PSS system making the power system simple without complications in PSS design and parameter optimization. The proposed controller application implements the LFOs’ control without a linearized mathematical model of the system, as such it makes the system less complex and bulky. Single machine infinite bus (SMIB) test system was simulated in SIMULINK domain with the PSSs and with the proposed controller to compare the NFC effectiveness. The simulation outcome for the eigenvalue study with NFC stabilizer yields steady eigenvalues that enhanced the damping status of the system greater than 0.1 with decreased overshoots and time to rise via the proposed NFC process than with the conventional FFA-PSS. Similarly, the generator transient reaction also presents the ω and δ based on the time to settle was improved by 64.66% and 28.78%, respectively, via the proposed NFC process than with the conventional FFA-PSS. Finally, the conventional PSS was found to be complicated in its design, parameter optimization and less effective than the proposed controller for the LFOs’ control.


Energies ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 725 ◽  
Author(s):  
Athanasios Dagoumas

Cybersecurity is an emerging challenge for power systems, as it strongly affects their reliability and the whole energy system cost. The paper uses several Unit Commitments (UC) models, applying different methods to tackle renewables’ uncertainty. The selected power system is IEEE RTS 96. The UC models are used to assess the impact of different cybersecurity threats. The focus is to assess their impact on the total operating cost and the power grid adequacy to handle them. The comparison between the UC models shows that more robust UC models lead to higher total operating costs. The cost, unit dispatching, and energy mix evolution have a non-linear trend, depending on the power system characteristics and the cyberattacks types. However, the paper provides evidence of considerable price signals in the case of the examined cyberattacks. Each Transmission System Operator (TSO) should examine combinations of cyberattacks and operating conditions to identify crucial cases for system stability and power system cost operation. The applied methodology would also require substantial developments or supplementary approaches to assess cyberthreats at the distribution level.


2013 ◽  
Vol 64 (6) ◽  
pp. 366-370 ◽  
Author(s):  
Duraiswamy Murali ◽  
Marimuthu Rajaram

Abstract The objective of this paper is to investigate the power system damping enhancement via power system stabilizers (PSSs). However, the conventional power system stabilizers (CPSSs) have certain drawbacks. There are many techniques proposed in the literature for damping improvement of low frequency power system oscillations. In this paper, adaptive neuro-fuzzy inference system (ANFIS) technology has been proposed to coordinate the CPSSs in a multi-machine power system. The time-domain simulations are carried out in Matlab/Simulink environment to validate the effectiveness of the proposed control scheme under different operating conditions.


Author(s):  
Boonrat Somritvanitcha ◽  
Issarachai Ngamroo ◽  
Komsan Hongesombut

ObjectStab is a general purpose simulation tool for power system stability studies developed by Modelica which is an object-oriented modeling language. It provides enough modeling flexibility to allow addition or modification of new power system components. This paper describes an incorporated use of fuzzy logic toolbox in Matlab/Simulink and Object-Stab library to enhance the application of this library into fuzzy control design environment. The example provided here is the modeling of the static synchronous series compensator (SSSC) which is the new device developed in the ObjectStab. In addition, the interface of ObjectStab with Matlab/Simulink for an SSSC damping controller design by fuzzy logic toolbox is explained step by step. Simulation studies in a multi-machine power system confirm the effectiveness of the designed fuzzy controller.


2021 ◽  
Author(s):  
Guilherme Penha da Silva Júnior ◽  
Thiago Figueiredo do Nascimento ◽  
Luciano Sales Barros

The high integration of distributed generation (DG) system based on renewable energy sources (RES) in the power system requires changes regarding the control mode of these sources with some urgency. Such changes seek to maintain the stability of the power systems. Thus, there is a demand for using control techniques on DGs/RESs that can mitigate the disturbances caused by low inertia and the lack of control over the dispatched powers. As a solution, one can use virtual synchronous generator (VSG) techniques making the voltage  source inverter (VSI) control behave similarly to the traditional synchronous generator (SG). This paper presents a literature review and performance tests for the main VSG topologies used in DGs/RESs: ISE, VSYNC, VISMA and Synchronverter. The implementation of VSG in the DGs/RESs has made possible increase inertia in the grid and, additionally regulate the active and reactive powers separately and bidirectionally. So, it has been possible to meet power system requirements; being able to operation both grid-connected or island-mode, which is ideal for microgrids. The results obtained confirm the literature reports. It was observed that the Synchronverter topology presented advantages over the other VSG topologies.


With the evolution of electrical networks, the complexity and non linearity of modern power systems has enhanced exponentially. In order to reduce these potentially harmful oscillations, power system stabilizers (PSS) are introduced in generators of modern power systems. The PSS brings the system back to a stable and balanced state and re-establishes the pre-fault performance of the system after removal of disturbance and restoration of line. However utilization of PSS in certain cases of increased transmission line loading and other significant faults is not very effective and is rather time consuming. These days to acquire better control and quality of power, FACTS devices are being commonly used in large power systems. When SVC, a versatile FACTS device is used simultaneously with PSS, there is not only improvement in power transfer capability and controllability but also a distinct enhancement in power system stability. In order to increase the performance of the conventional PID controller of the PSS, it is tuned with a very simple and quick tuning method called Zeigler Nichols (ZN) which provides very fast elimination to disturbances in power system. However the conventional and ZN based PID controllers are confined only to linear control of power system. To further enhance the dynamic tuning process in order to obtain much faster and better transient as well as dynamic stability, a very adaptable and robust nature inspired technique of Flower Pollination Algorithm (FPA) is used to tune the ZN based PID controller. To realise the system transient stability for the conventional and proposed method, root locus and total harmonic distortion techniques have been adopted. The results ultimately reveal the efficacy and productiveness of FP based ZN- PID in successfully damping out inter area oscillations thus reducing the harmonics and improving overall stability in power systems as compared to other tuning methods


Electronics ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 247
Author(s):  
Herlambang Setiadi ◽  
Rakibuzzaman Shah ◽  
Md Rabiul Islam ◽  
Dimas Anton Asfani ◽  
Tigor Hamonangan Nasution ◽  
...  

Maintaining power system stability in renewable-rich power systems can be a challenging task. Generally, the renewable-rich power systems suffer from low and no inertia due to the integration of power electronics devices in renewable-based power plants. Power system oscillatory stability can also be affected due to the low and no inertia. To overcome this problem, additional devices that can emulate inertia without adding synchronous machines can be used. These devices are referred to as virtual synchronous machines (VISMA). In this paper, the enhancement of oscillatory stability of a realistic representative power system using VISMA is proposed. A battery energy storage system (BESS) is used as the VISMA by adding an additional controller to emulate the inertia. The VISMA is designed by using Fruit Fly Optimization. Moreover, to handle the uncertainty of renewable-based power plants, the VISMA parameters are designed to be adaptive using the extreme learning machine method. Java Indonesian Power Grid has been used as the test system to investigate the efficacy of the proposed method against the conventional POD method and VISMA tuning using other methods. The simulation results show that the proposed method can enhance the oscillatory stability of the power system under various operating conditions.


2012 ◽  
Vol 2 (1) ◽  
Author(s):  
Guo-Jie Li ◽  
Tek Lie

AbstractInter-area oscillations are serious problems to large-scale power systems. A decentralized H ∞ generator excitation controller of a power system is proposed to damp the inter-area oscillations and to enhance power system stability. The design procedure for a linear composite system is presented in terms of positive semi-definite solutions to modified algebraic inequalities. The resulting controller guarantees closed-loop stability, robustness and an H ∞-norm bound on disturbance attenuation even under uncertainties such as high frequency noise. The control is decentralized in the sense that the control of each generator depends on local information only. The effectiveness of the H ∞ controller is demonstrated through digital simulation studies on a two-machine power system.


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