Distributed optimal-tracking control to coordinate the optimization of active distribution networks with automatic generation control

Xingxu Zhu ◽  
Xueshan Han ◽  
Yijing Xu ◽  
Junhui Li
Aurobindo Behera ◽  
Tapas K. Panigrahi ◽  
Arun K. Sahoo

Background: Power system stability demands minimum variation in frequency, so that loadgeneration balance is maintained throughout the operation period. An Automatic Generation Control (AGC) monitors the frequency and varies the generation to maintain the balance. A system with multiple energy sources and use of a fractional controller for efficient control of stability is presented in the paper. At the outset a 2-area thermal system with governor dead band, generation rate constraint and boiler dynamics have been applied. Methods: A variation of load is deliberated for the study of the considered system with Harmony Search (HS) algorithm, applied for providing optimization of controller parameters. Integral Square Time Square Error (ISTSE) is chosen as objective function for handling the process of tuning controller parameters. : A study of similar system with various lately available techniques such as TLBO, hFA-PS and BFOA applied to PID, IDD and PIDD being compared to HS tuned fractional controller is presented under step and dynamic load change. The effort extended to a single area system with reheat thermal plant, hydel plant and a unit of wind plant is tested with the fractional controller scheme. Results: The simulation results provide a clear idea of the superiority of the combination of HS algorithm and FO-PID controller, under dynamically changing load. The variation of load is taken from 1% to 5% of the connected load. Conclusion: Finally, system robustness is shown by modifying essential factors by ± 30%.

2021 ◽  
Vol 11 (3) ◽  
pp. 1211
En-Chih Chang ◽  
Chun-An Cheng ◽  
Rong-Ching Wu

This paper develops a full-bridge DC-AC converter, which uses a robust optimal tracking control strategy to procure a high-quality sine output waveshape even in the presence of unpredictable intermissions. The proposed strategy brings out the advantages of non-singular fast convergent terminal attractor (NFCTA) and chaos particle swarm optimization (CPSO). Compared with a typical TA, the NFCTA affords fast convergence within a limited time to the steady-state situation, and keeps away from the possibility of singularity through its sliding surface design. It is worth noting that once the NFCTA-controlled DC-AC converter encounters drastic changes in internal parameters or the influence of external non-linear loads, the trembling with low-control precision will occur and the aggravation of transient and steady-state performance yields. Although the traditional PSO algorithm has the characteristics of simple implementation and fast convergence, the search process lacks diversity and converges prematurely. So, it is impossible to deviate from the local extreme value, resulting in poor solution quality or search stagnation. Thereby, an improved version of traditional PSO called CPSO is used to discover global optimal NFCTA parameters, which can preclude precocious convergence to local solutions, mitigating the tremor as well as enhancing DC-AC converter performance. By using the proposed stable closed-loop full-bridge DC-AC converter with a hybrid strategy integrating NFCTA and CPSO, low total harmonic distortion (THD) output-voltage and fast dynamic load response are generated under nonlinear rectifier-type load situations and during sudden load changes, respectively. Simulation results are done by the Matlab/Simulink environment, and experimental results of a digital signal processor (DSP) controlled full-bridge DC-AC converter prototype confirm the usefulness of the proposed strategy.

2014 ◽  
Vol 2014 (10) ◽  
pp. 538-545 ◽  
Abdul Basit ◽  
Anca Daniela Hansen ◽  
Mufit Altin ◽  
Poul Sørensen ◽  
Mette Gamst

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