Impact of hybrid FACTS devices on the stability of the Kenyan power system

<p>Flexible alternating current transmission system (FACTS) devices are deployed for improving power system’s stability either singly or as a combination. This research investigates hybrid FACTS devices and studies their impact on voltage, small-signal and transient stability simultaneously under various system disturbances. The simulations were done using five FACTS devices-static var compensator (SVC), static synchronous compensator (STATCOM), static synchronous series compensators (SSSC), thyristor controlled series compensator (TCSC) and unified power flow controller (UPFC) in MATLAB’s power system analysis toolbox (PSAT). These five devices were grouped into ten pairs and tested on Kenya’s transmission network under specific contingencies: the loss of a major generating machine and/or transmission line. The UPFC-STATCOM pair performed the best in all the three aspects under study. The settling times were 3 seconds and 3.05 seconds respectively for voltage and rotor angle improvement on the loss of a major generator at normal operation. The same pair gave settling times of 2.11 seconds and 3.12 seconds for voltage and rotor angle stability improvement respectively on the loss of a major transmission line at 140% system loading. From the study, two novel techniques were developed: A performance-based ranking system and classification for FACTS devices.</p>

Optimal Setting of Thyristor Controlled Series Compensator with Brain Storm Optimization Algorithms for Available Transfer Capability Enhancement

Applications of Flexible AC Transmission Systems (FACTS) devices for enhancement of Available Transfer Capability (ATC) is gaining attention due to economic and technical limits of the conventional methods involving physical network expansions. FACTS allocation which is sine-qua-non to its performance is a major problem and it is being addressed in recent time with heuristic algorithms. Brain Storm Optimization Algorithms (BSOA) is a new heuristic and predicting optimization algorithms which revolutionizes human brainstorming process. BSOA is engaged for the optimum setting of FACTS devices for enhancement of ATC of a deregulated electrical power system network in this study. ATC enhancement, bus voltage deviation minimization and real power loss regulation are formulated into multi-objective problems for FACTS allocation purposes. Thyristor Controlled Series Capacitor (TCSC) is considered for simulation and analyses because of its fitness for active power control among other usefulness. ATC values are obtained for both normal and N-1-line outage contingency cases and these values are enhanced for different bilateral and multilateral power transactions. IEEE 30 Bus system is used for demonstration of the effectiveness of this approach in a Matlab software environment. Obtained enhanced ATC values for different transactions during normal evaluation cases are then compared with enhanced ATC values obtained with Particle Swarm Optimization (PSO) set TCSC technique under same trading. BSO behaved much like PSO throughout the achievements of other set objectives but performed better in ATC enhancement with 27.12 MW and 5.24 MW increase above enhanced ATC values achieved by the latter. The comparative of set objectives values relative to that obtained with PSO methods depict suitability and advantages of BSOA technique.

A Comprehensive Analysis of DSTATCOM-Based Power Improvement

Power quality became one of the most critical challenges in today’s modern power system. Utmost primary factors of power quality issues are non-linear fluctuating loads, system interruption, load variances, infrequent loads, and arc furnaces. As a matter of fact, there is occurrence of various electrical distortions, along with voltage spikes, voltage sags, and so forth. Several innovative techniques were employed for the development of circuits which resulted in minimised voltage stability as well as reliability. Utility companies which are electrical are receiving a large quantity of complaints because of these challenges. An approach is required now to explore the power quality challenges in industrial sector, corporate sector, municipal, or domestic sites. Therefore, a few techniques known as Flexible AC transmission system (FACTs) are used to enhance power quality. It is divided into two categories: namely series-FACTs and shunt-FACTS. As name itself define its architecture that in series-FACTS comprised of transmission line which is connected in series with module and connected in parallel in shun-FACTs. We can alleviate the problems related to power quality with the help of these FACTS devices. D-STATCOM is one of the better devices available. D-STATCOM is a shunt-connected solid-state device employed at the distribution network to maintain load-side disturbances. It has exceeded the traditional capacitor being used improve power quality with it's lower upfront investment, outstanding dynamics, absence of static, and lower operational expenses. The sorts, architectural style, operating, control systems, and AI are all described in this article.

An efficient multi-objective based squirrel search optimization for optimal placement of FACTS devices

The adoption of a new transmission line is extremely complex because of its socio-economic problems such as environmental clearances. Thus, there is a prominence of better utility over available transmission infrastructure. The Flexible Alternating Current Transmission System (FACTS) devices can offer transmission capability enhancement, power compensation, and stability as well as voltage improvement. However, the FACTS devices have a higher penetration impact of wind generation for the dynamic stability of power networks. In this work, an efficient Intellectual Control system has been proposed to stabilize the FACTS devices placement. The Squirrel Search Optimization is adapted with an intellectual control system to enhance the steady-state voltage stability of FACTS devices. The proposed system has been evaluated with the assist of IEEE 14 and 26 standard bus systems to handle the multi-objective functions like cost, reduction in power loss, reducing risks, and maximizing user’s benefit. These multi-objective functions facilitate to attain the optimal placement and load flows at various sites. The simulation can be carried out with MATLAB/SIMULINK environment and the results manifest that the proposed system outperforms well when compared with existing approaches.

Voltage Stability Assessment of Grid Connected PV Systems With FACTS Devices

Three static techniques (i.e., Power flow, Continuation Power Flow (CPF), and the Q-V curve) were used to assess the voltage stability of the power grid with a Solar Photovoltaic Generator (SPVG) and FACTS devices under nominal and heavy loading conditions. A static model is proposed for the power system that includes conventional power generation units and SPVGs with FACTS devices. Two models of SPVG were used (i.e., PV model and PQ model) to elucidate the effect of the SPVGs on the voltage stability under various operating conditions. The best location for FACTS devices was obtained under nominal and heavy load conditions using static techniques. The series and shunt FACTS devices under nominal and heavy loading conditions were compared using the abovementioned static techniques. The interaction between SPVGs and FACTS devices is detailed in this paper. The proposed approach was tested on the New England 39-bus standard test system, and the results confirmed the effectiveness of the proposed method under various operating conditions.

Intelligent stability margin improvement using series and shunt controllers

Electric market always prefers to use full capacity of existing power system to control the costs. Flexible alternate current transmission system (FACTS) devices introduced by Electric Power Research Institute (EPRI) to increase the usable capacity of power system. Placement of FACTS controllers in power system is a critical issue to reach their maximum advantages. This article focused on the application of FACTS devices to increase the stability of power system using artificial intelligence. Five types of series and shunt FACTS controllers are considered in this study. Continuation power flow (CPF) analysis used to calculate the collapse point of power systems. Controlling parameters of FACTS devices including their locations are determined using real number representation based genetic algorithm (RNRGA) in order to improve the secure margin of operating condition of power system. The 14 and 118 buses IEEE standard test systems are utilized to verify the recommended method. The achieved results manifestly proved the effectiveness of proposed intelligent method to increase the stability of power system by determining the optimum location and size of each type of FACTS devices.