Microsoft Word - ETASR_V13_N4_pp11490-11496 Engineering, Technology & Applied Science Research Vol. 13, No. 4, 2023, 11490-11496 11490 www.etasr.com Rajderkar & Chandrakar: Security Enhancement through the Allocation of a Unified Power Flow … Security Enhancement through the Allocation of a Unified Power Flow Controller (UPFC) in a Power Network for Congestion Management Vedashree P. Rajderkar Department of Electrical Engineering, G H Raisoni College of Engineering, India vedashree.rajderkar@raisoni.net (corresponding author) Vinod K. Chandrakar Department of Electrical Engineering, G H Raisoni College of Engineering, India v12k5c63@gmail.com Received: 31 May 2023 | Revised: 22 June 2023 and 7 July 2023 | Accepted: 8 July 2023 Licensed under a CC-BY 4.0 license | Copyright (c) by the authors | DOI: https://doi.org/10.48084/etasr.6075 ABSTRACT The electricity demand is continuously increasing, so a most efficient use of the current power system's capacity is desired. Flexible AC Transmission Systems (FACTSs), a recently developed transmission technology, are widely used to boost the power transfer ability of long-distance transmission line networks and to enhance the consistency of the transmission systems. The use of FACTS devices can lead to reduced flows on heavily loaded lines, targeted bus voltage levels, and better power network stability. In this study, an optimization method based on the optimal position of the Unified Power Flow Controller (UPFC) is suggested to boost system security. It is decided that the real power flow is the best place for the UPFC in this instance. The optimal placement during congestion has been determined using the Genetic Algorithm (GA) and the sensitivity to the useful power flow index. Congestion is produced on the network and system performance is evaluated. The proposed solutions are evaluated in the IEEE 30 bus network before being implemented in MATLAB. In the case of congestion, the security of the network is evaluated after connecting the UPFC. The effectiveness of the proposed solution was verified with the help of the Power World Simulator 16.0. Keywords-UPFC; sensitivity to useful power flow index; genetic algorithm; location optimization; security I. INTRODUCTION Modern large and complex networks are delivering under stress as a result of the ongoing increase in demand. The utilities are forced to deal with continuous I 2 R loss, line overloads, and variations in bus voltage. Power transmission systems require more capacity, flexibility, reliability, and security. Electric utility companies search for various strategies to effectively use the existing transmission lines up to their working capacity. However, this has the side effect of raising the possibility of system instability while security issues emerge. On improving the network security, techniques that relieve stress have received much attention. Line overloads have been addressed using load shedding and generation rescheduling methods. Load shedding is frequently regarded as the last choice because it will interrupt the power supply of some customers. The operational costs associated with generation rescheduling are fairly substantial. The use of FACTS devices to redistribute power is preferred in order to solve line overload problems since it offers a financially appealing technique of resolving line overloads without switching off power. FACTS devices are frequently applied in networks to ensure steady state and secure operation. FACTS devices can alter system settings such as useful power, MVAR power, and node voltage and are incorporated in the electrical networks to improve their flexibility, stability and security. UPFC is considered to be a part of the most recent generation of FACTS. The UPFC efficiently redistributes power within the power network. Additionally, an existing transmission line can have a UPFC built on it, something that requires less space than adding a new transmission corridor. Due to the extremely high power flow control speeds of UPFCs, overloads brought on by component failures or intermittent generation can potentially be immediately relieved. However, the number of UPFC devices and the complexity of the power system enhance combinatorically the viable zone and the constraints to be taken into consideration in optimization approaches. Authors in [1] explain that the line loading is tracked in real-time performance and can be kept under their thermal tolerance by a quick and effective dynamic response management of the UPFC. In [2], the authors describe the SCOPF simulation used to decide the appropriate place for UPFC in the standard network under higher load circumstances According to [3], the use of UPFC may effectively decrease the N-1 congestion issue of Engineering, Technology & Applied Science Research Vol. 13, No. 4, 2023, 11490-11496 11491 www.etasr.com Rajderkar & Chandrakar: Security Enhancement through the Allocation of a Unified Power Flow … transmission channels running North to South and has a significant cost superiority over the old method. Authors in [4] suggest incorporating a UPFC into a Newton-Raphson load flow method. The created UPFC model is based on a power injection strategy that considers four control modes to manage the voltage amplitude of a given node, the useful and MVAR powers flow in a line concurrently or selectively. In [5], the best place of a DPFC in a network was suggested, followed by the optimum placement of two DPFCs in a system. The artificial algae method is used for the optimal placement of the DPFC in the electrical system. In [6], the authors present and execute a 161 kV UPFC model on an 11-bus network. The weakest bus is located by using FVSI, and the most vital line was identified using MLA. Authors in [7] examine dynamic stability, proposing a method that uses a hybrid strategy to identify the best placement and size of the UPFC. Authors in [8] utilized the conventional strategy to place the TCSC and UPFC in the best possible location for boosting system security under various operating situations and at the best FACTS parameter values. Authors in [9] discuss various methods for reducing congestion, such as load shedding, GA, PSO, MINLP, SFLA, and Fuzzy Logic Systems. The best location for DG, Nodal Pricing, and cost-free methods are also discussed. In [10], the authors suggested a full-featured, reliable and adaptable model for ESS and UPFC together after briefly reviewing the models that are now in use, including the decoupled, power injection, and voltage source models. In order to reduce total grid losses, authors in [11], use the Tabu search algorithm based on an improved HS method to represent an optimization challenge for an I grid. Authors in [12], discuss how FACTS devices can enhance a transmission line's ability to handle power and maintain Voltage. Numerous researches have discussed the ideal location for UPFC [13–16]. However, they are not concerned with the verification of the software- based congestion forecast. The location of UPFC based on congestion management by using sensitivity based methods and GA in order to relive the congestion and to enhance the power system security and reliability is discussed in this paper. The results are validated by using Power World Simulator (PWS). This investigation offers the ideal positioning for UPFC based on the useful power flow performance index approach. The fact that the active power flow assessment index is a reliable indication of useful power security, a decrease in Performance Indicator (PI) caused by the placement of the FACTS controller will improve network security. The location of these devices in the network was determined using the sensitivity of PI with regard to the FACTS control variables which is comparable to UPFC location determined by GA, for strengthening the security of system during congestion management. The decision on the placement of the UPFC is made in accordance with the results, and verified was with the PWS, II. UPFC DESIGN For steady state conditions, UPFC static modeling was created. Series and shunt converters were combined to create UPFC. Voltage (VS), Insertion angle in a series with line (ϕs), and an element of shunt current (Iq), which is in quadrature with voltage Vi at the UPFC's i th bus, are the three control parameters for UPFC [8]. The equivalent circuit of the line incorporating the UPFC is described in Figure. 1. When a line includes UPFC, its apparent powers are expressed as: ��� = −����� − 2�� �� �� cos�∅� − ��� + � �� ��� cos�∅� − � � + �� sin�∅� − � �� (1) ��� = �� �� + �� �� ��� sin�∅� − �� � + �� cos�∅� − �� �� (2) � � = � �� ��� cos�∅� − � � − �� sin�∅� − � �� (3) � � = −� �� ��� sin�∅� − � � + �� cos�∅� − � �� (4) �� = !� + "� #�$ # $ Fig. 1. FACTS controller model. A. Power World Simulator Software based UPFC Model A systematic approach is developed to simultaneously control real power, MVAR power, and bus voltages [10]. The useful power, MVAR power, or the voltage of each node can be used to secure the network. If the bus element is neutral to the bus parameters, the power flow solution is constant. UPFC is connected in the line and always maintains the voltage (VEt) in sending bus i and injects PBt-QBt at the receiving end to bus j as illustrated in Figure 2. Under loss-free UPFC, the power values for bus i and bus j would be equal as indicated in Figure 3. The UPFC sending end's known values are PEt and VEt. When UPFC is implemented at the sending, according to the design, an additional bus must be added to the network in the PWS [10]. If a UPFC is developed in the center of the line, the network will need to add two buses. Fig. 2. UPFC power flow model. Fig. 3. UPFC static model. Engineering, Technology & Applied Science Research Vol. 13, No. 4, 2023, 11490-11496 11492 www.etasr.com Rajderkar & Chandrakar: Security Enhancement through the Allocation of a Unified Power Flow … III. UPFC CONTROLLER PLACEMENT METHODOLOGY The reserve capacity of the transmission system has a partial representation in load ratio. Additionally, the reserve capacity increases as the load rate decreases. Therefore, increasing the transmission capacity of overloaded lines could meet the needs of increasing load. Regarding accident prevention, both the stability state and the typical power flow of the system are examined. After that, the system starts to use congestion management. Here, the real power flow performance index and GA are used to calculate the maximum power flow and the most suitable position for placing the UPFC is selected. The system returns to regular operation and security is enhanced after attaching the UPFC. A. Sensitivity-Based Method The performance of the line under routine and emergency circumstances affects the active power flow Performance Indicator (PI). The active power flow PI [8] technique can be used to describe the loadability of the system's functionality: �� = ∑ &'�( ) *+' *+'',- . �(/+ 012 (5) where, wm =1, Nl is the total number of lines in the system, wm is a real non-negative weighting coefficient, �30045 is the maximum load capacity of the line, �30 is the actual power flow in the line, and n = 2. The degree of severity is determined by the system's loading circumstances in both normal and emergency situations. The sensitivity technique is used to analyze the system's performance. Low PI value means an operation within thermal limits under steady state conditions. The value of PI rises when an overloaded condition is reached. In this article, the active power flow performance indicator approach is used to decide where to allocate UPFC in relation to series insertion angle (ϕs) as shown below: 6�7 = 8*9:;8∅< =∑ =0�30>/+012 ) 2*+'',-. ? 8*+':<8∅< (6) The real power injection in the line is taken into consideration when computing DC power flow equation [8] : �30 = @∑ #0( �( ABC D E F, /(12(H�∑ #0( �(/(12(H� � � ABC D = F (7) According to Figure 1, the UPFC is situated in line k, which connects buses i and j. Pj is the additional electrical power that UPFC in the system injects into the line. The network has N buses, and Smn is the mn th part of the power flow matrix [S]. The following equation can be created by combining (6) and (7): 8*+':<8∅< = @ I#0� 8*J<:<8∅< � #0 8*K< :<8∅