In this paper a novel non-linear optimization problem is formulated to maximize the social welfare in restructured environment with generalized unified power flow controller (GUPFC). This paper presents a methodology to optimally allocate the reactive power by minimizing voltage deviation at load buses and total transmission power losses so as to maximize the social welfare. The conventional active power generation cost function is modified by combining costs of reactive power generated by the generators, shunt capacitors and total power losses to it. The formulated objectives are optimized individually and simultaneously as multi-objective optimization problem, while satisfying equality, in-equality, practical and device operational constraints. A new optimization method, based on two stage initialization and random distribution processes is proposed to test the effectiveness of the proposed approach on IEEE-30 bus system, and the detailed analysis is carried out.
Transmission line loss minimization in a power system is an important research issue and it can be achieved by means of reactive power compensation. The unscheduled increment of load in a power system has driven the system to experience stressed conditions. This phenomenon has also led to voltage profile depreciation below the acceptable secure limit. The significance and use of Flexible AC Transmission System (FACTS) devices and capacitor placement is in order to alleviate the voltage profile decay problem. The optimal value of compensating devices equires proper optimization technique, able to search the optimal solution with less computational burden. This paper presents a technique to provide simultaneous or individual controls of basic system parameter like transmission voltage, impedance and phase angle, thereby controlling the transmitted power using Unified Power Flow Controller (UPFC) based on Bacterial Foraging (BF) algorithm. Voltage stability level of the system is defined on the Fast Voltage Stability Index (FVSI) of the lines. The IEEE 14-bus system is used as the test system to demonstrate the applicability and efficiency of the proposed system. The test result showed that the ocation of UPFC improves the voltage profile and also minimize the real power loss.
[1] Edris A.A., Aapa R., Baker M.H., Bohman L., Clark K., Proposed terms and definitions for flexible ac transmission system (FACTS), IEEE Trans. on Power Delivery, vol. 12, no. 4, pp. 1848–1853 (1997), DOI: 10.1109/61.634216.
[2] Das D., Divan D.M., Harley R.G., Power flow control in networks using controllable network transformers, IEEE Trans. Power Electron., vol. 25, no. 7, pp. 1753–1760 (2010), DOI: 10.1109/ TPEL.2010.2042076.
[3] Ooi B.T., Kazerrani M., Marcean R., Wolanski Z., Galiana F.D., Megillis D., Jms G., Midpoint siting of FACTS devices in transmission lines, IEEE Trans. on power delivery, vo1. 12, no. 4, pp. 1717–1722 (1997), DOI: 10.1109/61.634196.
[4] Hingorani N.G., Gyugyi L., Understanding FACTS: Concepts and Technology of Flexible AC Transmission Systems, New York: IEEE Press (2000).
[5] Nabavi-Niak A., Iravani M.R., Steady-State and Dynamic Models of Unified Power Flow Con- troller (UPFC) for Power System Studies, IEEE Trans. Power Systems, vol. 11, no. 4 (1996), DOI: 10.1109/59.544667.
[6] Harjeet Johal, Deepak Divan, Design Considerations for Series-Connected Distributed FACTS Converters, IEEE Transactions on Industry Applications, vol. 43, iss. 6, pp. 1609–1618 (2007), DOI: 10.1109/TIA.2007.908174.
[7] Amir Hamidi, Sajjad Golshannavaz, Daryoush Nazarpour, D-FACTS Cooperation in Renewable Inte- grated Microgrid A Linear Multiobjective Approach, IEEE Transactions on Sustainable Energy, vol. 10, iss. 1, pp. 355–363 (2019), DOI: 10.1109/TSTE.2017.2723163.
[8] Narasimha Rao D., Srinivasa Varma P., Comparison of UPFC and DPFC, Journal of Critical Reviews, vol. 7, iss. 6 (2020), DOI: 10.31838/jcr.07.06.153.
[9]Abhilash Sen, Atanu Banerjee, Haricharan Nannam, A Comparative Analysis between UPFC and DPFC in a Grid Connected Photovoltaic System, IEEE International Conference on Intelligent Techniques in Control, Optimization and Signal Processing (INCOS) (2019), DOI: 10.1109/IN- COS45849.2019.8951352.
[10] Song W., Zhou X., Zhigang Liang, Subhashish Bhattacharya, Huang Alex Q., Modeling and Control Design of Distributed Power Flow Controller based-on Per-phase control, IEEE Energy Conversion Congress and Exposition (2009), DOI: 10.1109/ECCE.2009.5316307.
[11] Chandrakar V.K., Kothari A.G., Optimal Location for Line Compensation by Shunt Connected FACTS Controller, IEEE Power Electronics and Drive Systems Conference, vol. 1, pp. 151–156 (2003), DOI: 10.1109/PEDS.2003.1282736.
[12] Vikash Anand, Sanjeev Kumar Mallik, Power flow analysis and control of distributed FACTS de- vices in power system, Archives of Electrical Engineering, vol. 67, no. 3, pp. 545–561 (2018), DOI: 10.24425/123662.
[13] Zhihui Yuan, de Haan Sjoerd W.H., Ferreira Jan A., Construction and first result of a scaled transmis- sion system with the Distributed Power Flow Controller (DPFC), 13th European Conference on Power Electronics and Applications (2009).
[14] Zhihui Yuan, de Haan Sjoerd W.H., Braham Frreira, Dalibor Cevoric, A FACTS Device: Dis- tributed Power Flow Controller (DPFC), IEEE Trans. Power Electronics, vol. 25, no. 10 (2010), DOI: 10.1109/TPEL.2010.2050494.
[15] Syona Chawla, Sheetal Garg, Bhawna Ahuja, Optimal Location of Series-Shunt FACTS Device for Transmission Line Compensation, IEEE Control, Automation, Communication and Energy Conservation Conference, pp. 1–6 (2009).
[16] Shehata Ahmed A., Refaat Ahmed, Mamdouh K. Ahmed, Korovkin Nikolay V., Optimal placement and sizing of FACTS devices based on Autonomous Groups Particle Swarm Optimization technique, AEE, vol. 70, no. 1, pp. 161–172 (2021), DOI: 10.24425/aee.2021.136059.
[17] Riadh Essaadali, Anwar Jarndal, Ammar B. Kouki, Fadhel M. Ghannouch, Conversion Rules Between X-Parameters and Linearized Two-Port Network Parameters for Large-Signal Operating Conditions, IEEE Transactions on Microwave Theory and Techniques, vol. 66, no. 11, pp. 4745 4756 (2018), DOI: 10.1109/TMTT.2018.2863227.
[18] Divya S., Shyamala U., Power quality improvement in transmission systems using DPFC, IEEE 2nd International Conference on Electronics and Communication Systems (ICECS) (2015), DOI: 10.1109/ ECS.2015.7125035.
[19] Apolinar Reynoso-Hernández J., Pulido-Gaytán M.A., Cuesta R., Loo-Yau J.R., Maya-Sánchez M.C., Transmission Line Impedance Characterization Using an Uncalibrated Vector Network Analyzer, IEEE Microwave and Wireless Components Letters, vol. 30, no. 5, pp. 528–530 (2020), DOI: 10.1109/ LMWC.2020.2984377.
[20] Monika Sharma, Annapurna Bhargava, Pinky Yadav, Oscillation Damping with DPFC Using Opti- mization Techniques, IEEE International Conference on Micro-Electronics and Telecommunication Engineering (ICMETE) (2017), DOI: 10.1109/ICMETE.2016.73.
[21] Mengmeng Xiao, Shaorong Wang, Yong Huang, Chao Zheng, Qiushi Xu, Hongsheng Zhao, Aihong Tang, Dichen Liu, Two-Level Control Method for DPFC Series Units Based on PLC Communication, 2nd IEEE Conference on Energy Internet and Energy System Integration (EI2), pp. 20–22 (2018), DOI: 10.1109/EI2.2018.8582109.
[22] Zhai X., Tang A., Zou X., Xu Zheng, Qiushi Xu, Research on DPFC Capacity and Parameter Design Method, IEEE International Conference on Information Technology, Big Data and Artificial Intelligence (ICIBA) (2020), DOI: 10.1109/ICIBA50161.2020.9277315.
[23] Pradhan A.K., Routray A., Banaja Mohanty, Maximum efficiency of flexible AC transmission systems, Electrical Power and Energy Systems, vol. 28, pp. 581–588 (2006), DOI: 10.1016/j.ijepes.2006.03.014.
[24] Seyed Abbas Taher, Muhammad Karim Amooshahi, New approach for optimal UPFC placement using hybrid immune algorithm in electric power systems, International Journal of Electrical Power and Energy Systems, vol. 43, iss. 1, pp. 899–909 (2012), DOI: 10.1016/j.ijepes.2012.05.064.
The uncontrolled power flow in the AC power system caused by renewable energy sources (restless sources, distributed energy sources), dynamic loads, etc., is one of many causes of voltage perturbation, along with others, such as switching effects, faults, and adverse weather conditions. This paper presents a three-phase voltage and power flow controller, based on direct PWM AC/AC converters. The proposed solution is intended to protect sensitive loads against voltage fluctuation and problems with power flow control in an AC power system. In comparison to other solutions, such as DVR, UPFC, the presented solution is based on bipolar matrix choppers and operates without a DC energy storage unit or DC link. The proposed solution is able to compensate 50% voltage sags, in the case of three-phase symmetrical voltage perturbation, and single phase voltage interruptions. Additionally, by means of a voltage phase control with a range of ±60◦ in each phase, it is possible to control the power flow in an AC power system. The paper presents an operational description, a theoretical analysis based on the averaged state space method and four terminal descriptions, and the experimental test results from a 1 kVA laboratory model operating under active load.