Doaa Khalil Ibrahim

Isolated microgrids (IMGs) power remote areas. However, IMG may lower the frequency stability and increase frequency excursions with low system inertia. Load frequency management ensures system stability. Thus, the paper proposes a novel multi-objective tuning strategy to improve IMG's load frequency control (LFC) and take the microgrid controller's control signals into account. Diesel engine generator, fuel cell, battery energy storage system, and renewable energy sources (RESs) like photovoltaic and wind systems make up the IMG. Conventional controllers such as proportional-integral (PI) and proportional integral derivative (PID) are classically tuned based on the standard error criteria as a traditional single-objective tuning approach. Due to the low inertia of the system and the stochastic nature of RES, they cannot act as required under different operating scenarios. Therefore, the PI and PID controllers are tuned using the proposed multi-objective-based tuning approach to reduce the frequency deviations. In addition, anti-windup is applied to the enhanced classic controllers to keep them distant from the nonlinear zone and beyond the source's physical constraints. The proposed tuning process also considers the maximum practical generation rates for different sources. The recent Artificial Rabbits Optimization (ARO) algorithm is applied to simultaneously adjust the controller parameters for several controlled sources in IMG. Extensive simulations in MATLAB and Simulink confirm the effectiveness of the proposed approach to keep the system stable even when facing high levels of disturbances. In addition, accomplishing sensitivity analysis, severe +-25% changes to the system's parameters guarantee that the proposed tuning strategy keeps the system stable.

Converting from a complete fossil fuel energy system to a decarbonized one is crucial to mitigating climate
change and protecting human health. Hybrid energy sources are better than producing energy from a single
technology. The combination of renewable energy and fuel generators allows users to cover seasonal fluctuations of resources and protects them from the unpredictability of fuel prices and supply. Nonetheless, the large-scale industrial demand presents a real challenge due to its consistency throughout the day and the intermittent nature of renewable sources. This research proposes a novel approach for optimal hybrid energy decarbonization for any demand type in general and industrial demand in particular. The proposed framework is developed by integrating the Hybrid Optimization of Multiple Energy Resources (HOMER) for the simulations of Hybrid Configurations (HCs), the Electrical Transient Analysis Program (ETAP) for the stability studies, and the Potentially All Pairwise RanKings of all possible Alternatives (PAPRIKA) method to rank the resulting configurations.
An industrial oil and gas complex with high wind and solar resource availability is adopted as a study case. It is
located in Abu Rudeis, Egypt, and currently utilizes only 11 Gas Turbine Generators (GTGs) to generate electricity. Five different HCs are investigated, including PV and wind systems. The proposed approach considers technical, environmental, economic, and socio-political criteria, with a total of 21 sub-criteria, and reveals that incorporating a wind farm of nine 2-MW wind turbines with the GTGs is the Optimal Hybrid Configuration (OHC).

Nowadays, the challenging errand is enhancing the wind energy system (WES) performance to be more competitive and economically viable. One of the best ways to enhance the performance of the doubly-fed induction generator (DFIG)-based-WES is the optimization of the proportional-integral (PI) controllers for the variable frequency converter system. Many objectives with different optimization techniques have been used in literature to achieve optimal performance. Each choice has its advantages and disadvantages. This paper presents a new design approach for better performance of PI controllers and, hence DFIG over a wide range of operating conditions through two main themes. The first is by introducing a new multi-objective formulation, while the second is utilizing recent optimization techniques like Grey Wolf Optimizer and Whale Optimization Algorithm. Four PI controllers are optimized using a traditional objective function and the proposed multi-objective formulation. Two are related to the Rotor Side Converter (RSC), named power regulator, and the main rotor side converter current regulator. The other two PI controllers related to Grid Side Converter (GSC) are the DC-link voltage regulator and the main grid-side converter current regulator. A performance comparison is held through normal and abnormal operating conditions on a simulation model of a 6 MW wind farm located in Jabal Alzayt along the Red Sea Coast in Egypt and directly connected to the grid. The results confirmed the effectiveness of the proposed approach to help the DFIG-based-WES to agree with the Egyptian Grid Code during disturbances compared with the traditional objective formulation.

In Egypt, the wind market increases quickly to make it one of the top countries in the Middle East. This
study discusses the viability of wind resources and the economic assessment for four locations in Egypt:
Ras El-Hekma, Farafra, Nuweiba, and Aswan through two stages. In the first stage, the optimal hub height
for some wind turbines has been calculated by using Equilibrium Optimizer (EO) algorithm to achieve
maximum wind energy with overall minimum cost. The second stage, the economic assessment has been
evaluated by using such turbines to calculate the cost of energy (COE) compared to the global and
Egyptian production costs of wind energy. Developed MATLAB programs are applied for statistical analysis
of wind data. The results have shown that Ras El-Hekma’s average wind speed is higher than other
sites and its wind energy potential is the best. Moreover, the economic assessment for selected locations
turns out that Ras El-Hekma by using EWT-DW61/22 turbine has the lowest COE.

This paper introduces a novel online adaptive protection scheme to detect and diagnose broken bar faults (BBFs) in induction motors during steady-state conditions based on an analytical approach. The proposed scheme can detect precisely adjacent and non-adjacent BBFs in their incipient phases under different inertia, variable loading conditions, and noisy environments. The main idea of the proposed scheme is monitoring the variation in the phase angle of the main sideband frequency components by applying Fast Fourier Transform to only one phase of the stator current. The scheme does not need any predetermined settings but only one of the stator current signals during the commissioning phase. The threshold value is calculated adaptively to discriminate between healthy and faulty cases. Besides, an index is proposed to designate the fault severity. The performance of this scheme is verified using two simulated motors with different designs by applying the finite element method in addition to a real experimental dataset. The results show that the proposed scheme can effectively detect half, one, two, or three broken bars in adjacent/non-adjacent versions and also estimate their severity under different operating conditions and in a noisy environment, with accuracy reaching 100% independently from motor parameters.

Nowadays, integrating large scale renewable energy sources, like solar PV parks, raises challenges for Load Frequency Controllers (LFC). The output of PV varies continuously, which requires a robust LFC deals
logically without continuous tuning and parameters optimization. In this paper, a fuzzy logic controller (FLC) is proposed to act as the main LFC instead of the traditional proportional–integral–derivative (PID) controller. The dynamic performance of FLC is enhanced by optimizing its parameters for different cost functions using particle swarm optimization technique (PSO). Another two FLCs will be added to PV system to act as an output controller instead of maximum power point tracker (MPPT) to enhance the overall system performance. To increase system reliability, a fast active power source called redox flow battery (RFB) is added in the proposed model as a frequency stabilizer. RFB can deeply discharge up to 90% with theoretically limitless number of duty cycles and has fast time response for severe load changes. The
importance of these proposed controllers side by side with RFB is to avoid disconnecting solar parks during
heavy cloudy days while preserving on maximizing its output during these periods. The superiority of the proposed FLC is examined by evaluating its performance compared to another control approach called PID-P (PID controller with P controller in the inner feedback loop). Finally, a comprehensive sensitivity analysis is also presented to investigate the controller robustness for extensive changes in power system parameters and loading.

Motors are the higher energy-conversion devices that consume around 40% of the global electrical generated energy. Induction motors are the most popular motor type due to their reliability, robustness, and low cost. Therefore, both condition monitoring and fault diagnosis of induction motor faults have motivated considerable research efforts. In this paper, a comprehensive review of the recent techniques proposed in the literature for broken bar faults detection and diagnosis is presented. This paper mainly investigates the fault detection methods in line-fed and inverter-fed motors proposed after 2015 and published in most relevant journals and conferences. The introduced review has deeply discussed the main features of the reported methods and compared them in many different aspects. Finally, the study has highlighted the main issues and the gaps that require more attention from researchers in this field.

With the widespread use of variable speed drives, a robust scheme that can detect and diagnose bearing faults under fixed and variable speed conditions becomes essential for reliable operation. Unfortunately, most of the reported methods in the literature are dedicated to working under fixed speed and will face challenges under variable speed conditions. Besides, most of them require detailed bearing information that may be unavailable in the real world. Therefore, in this paper, a new scheme is proposed for bearing faults detection and diagnosis under fixed and time varying speed conditions. The proposed scheme is based on the analysis of vibration signals using the persistence spectrum that can provide images rich with health-related features largely independent from rotating speed. Then, the produced image is compared with priorly stored images of the persistence spectrum of a healthy case. This comparison is performed using the multi-scale structural similarity index, which is a robust basis for images comparison without the need for training or expert knowledge. The obtained index is compared against an adaptive threshold for fault detection. Upon detecting a fault, the persistence spectrum image is compared with that of stored different fault types for fault diagnosis. The proposed scheme is extensively validated using three experimental datasets under different speed conditions. The results show that it can detect bearing faults in an earlier stage without the need for bearing specifications or shaft speed. Moreover, it can successfully diagnose bearing faults severity with accuracy reaching 100% with the minimum required data.

The distance protection in transmission networks is vulnerable to malfunction during a power swing. Distance relays have a power swing blocking (PSB) function that prevents the relay from operating during a power swing. However, during a power swing, the relay will be able to identify and clear any fault. This paper offers a scheme for detecting symmetrical/unsymmetrical faults through power swing by estimating the maximum rate of change of a (DI- DV) ellipse circumference.
The ellipse circumference of each phase is constructed at each power frequency cycle to consistently tracking the distinction in the measured current and voltage differences between the line’s two ends. The main feature of the suggested work compared to previous works is the ability to detect numerous high impedance faults (HIFs) during single mode (slow/fast) power swing or multi-mode power swing in addition to the opportunity to detect faults during asymmetrical power swing. The suggested scheme is tested in a two-area, four-machine power system and tested also in the standard three-machine, nine-bus system using ATP software. The results reveal that the improved protective scheme performs well in fault conditions with and without power swing, and they confirm the scheme’s suitability for interconnected networks.

This paper introduces a protection scheme for interconnected networks based on proposed Directional Overcurrent Relays (DOCRs) with user-defined two-level characteristics. By getting usage of the capabilities available in modern digital DOCRs, the proposed relay will have two user-defined characteristics; one for its primary operation and another for its backup operation (two-level characteristics) to fit a specific application or system. The coordination between the proposed relays is formulated and solved as a non-linear optimization problem to minimize their operating time and reduce the thermal impact caused by short circuit currents through electrical equipment while maintaining the technical constraints.
Extensive comparative studies have been performed to ensure the effectiveness of the proposed protection
scheme. Firstly, the performance of the traditional one-level characteristic relay (COLC) with two settings is
compared to the conventional two-level characteristic relay (CTLC) with three settings. Then a further investigation is carried out by suggesting increasing the number of settings to seven, named as the user-defined two-level characteristic relay (UDTLC), and then to nine settings, named as the shifted-user-defined two-level characteristic relay (SUDTLC). Finally, different multi-objective functions with proper weighting factors are investigated to determine the most effective one with the best performance for the proposed idea.
The distribution portion of the IEEE 30-bus system has been used to test and verify the proposed characteristics extensively. The optimal coordination problem is solved using the fmincon function in MATLAB. Based on the achieved results, the proposed characteristics of UDTLC and SUDTLC guaranteed a considerable reduction in operating times. In addition, the achieved results deduced that using a different multi-objective formulation has little impact on reducing operating time due to using the proposed characteristics UDTLC and SUDTLC, which means solving the coordination problem is mainly dependent on the applied characteristics.

Car exhaust is one of the most common causes of ozone hole aggravation, electrical vehicles (EVs) represent a promising solution to avoid this problem. Despite the benefits of EVs, their random charging behavior causes some difficulties regarding the electric network performance, such as increased energy losses and voltage deviations. This paper aims to achieve the proper scheduling of the EVs charging process, avoid its negative impacts on the network, and satisfy the EVs users’ requirements. The EVs charging process is formulated as an optimization problem and solved using particle swarm optimization. The optimization problem formulation considers the EV arrival and departure times and the state of charge required by the user. Different strategies such as separated, accumulated, and ranked strategies with continuous or interrupted fixed charging have been applied to solve the uncoordinated EVs charging problem. These strategies are extensively tested on the modified IEEE 31 bus system (499-node network), using the combination of both Open DSS and MATLAB m-files. The simulation results confirm the effectiveness of the proposed accumulated ranked strategy with interrupted fixed charging in improving the overall power system performance. The achieved improvements include minimizing: the peak power consumed, the peak power losses, and the voltage drop. Moreover, the cost of the EVs charging in most of the feeders has been decreased to a satisfying value. A comparison between the proposed strategy and some previously reported strategies has been performed to ensure the technical and economic enhancement of the proposed strategy.

Power swing is a power system transient phenomenon that arises due to several reasons including line switching, line outage, sudden increment or decrement in load, faults, etc. Unnecessary tripping during power swing and unnecessary blocking for faults occur during power swing result in distance relay maloperation. Several cascaded outages and major worldwide blackouts have occurred due to maloperation of distance relays. This paper proposes a technique for supervising distance relays during power swing. The proposed
online technique discriminates real faults and power swing accurately. It relies on constructing a locus diagram for the current and voltage differences (ΔI-ΔV) between the two ends of the protected line. The locus is estimated at every power frequency cycle to continuously monitor the state of the line by utilizing the synchrophasor measurements at the sending and receiving ends of the line. The proposed technique is tested for two-area, four-machine power system under faults at different locations of zone-1 and zone-2 regions of distance relays, fault resistances, fault inception angles and slip frequencies using MATLAB software. The simulation results proved the superior improvement of distance relay performance for handling power swing blocking and unblocking actions.

This paper proposes an adaptive dynamic Mho distance relay based on a phase comparator scheme for protecting interconnected transmission networks compensated with a Thyristor Controlled Series Capacitor (TCSC). The proposed relay uses an impedance index factor to initiate the fault detection subroutine. The RMS of the positive sequence current of the faulted loop and the TCSC terminal current are compared for TCSC zone identification. A phase comparator for ground and phase distance elements is proposed, relying on the positive sequence voltage as a polarized memory quantity, while the operating and polarizing quantities are developed using estimated TCSC impedance to mitigate its negative impact. The proposed scheme is easy in implementation and independent on synchronized data transfer, as minimum communication requirements are needed. To evaluate the performance of the proposed scheme, extensive simulation studies were carried out on an IEEE9 bus system compensated with TCSC for different firing angles covering four modes of TCSC operations, different fault types, and fault locations. In addition, an IEEE-39 bus network, as a large interconnected system, is tested for validation purposes. The achieved results designate the precision of the proposed scheme. Moreover, the results indicate its effectiveness for fault resistance tolerance, close-in three phase faults, and stable power swing phenomenon compared with conventional relays.

Most of the published research studies for detecting induction motor broken bar faults (BBFs) use a time–frequency (t − f ) decomposition tool to characterize the fault-related components. However, the identification and the assessment of these components in (t − f ) domain require skilled user or powerful pattern recognition technique. Moreover, a relatively long starting duration is necessary. This article introduces an automated scheme to detect BBFs and distinguish fault severity in induction motors under startup conditions regardless of the user experience and even under short starting duration and in a noisy environment. This scheme is based on the analysis of the starting current using optimized Stockwell transform (ST). An active set algorithm is applied to maximize the energy concentration of the left-side harmonic (LSH) component. Then, an adaptive time–frequency filter is applied to extract the LSH component from the (t − f ) domain, where the energy of the right part of LSH (RLSH) is utilized as an effective index for BBFs detection and for discriminating BBFs severity. Both real experimental data and simulation-based tests on 0.746- and 11-kW motors are used to extensively verify the performance of the proposed scheme. The achieved results have ensured that the proposed scheme can achieve a high accuracy with the minimum data and shortest acquisition time in comparison with some recent methods in the literature.

A two-fold adaptive dynamic quadrilateral relay is developed in this research for protecting
Thyristor-Controlled Series Compensator (TCSC)-compensated transmission lines (TLs). By
investigating a new tilt angle and modifying the Takagi method to recognize the fault zone identifier,
the proposed relay adapts its reactive reach and resistive reach separately and independently. The
investigated tilt angle and identified fault zone use the TCSC reactance to compensate its effect
on the TL parameters and system homogeneity. Excessive tests are simulated by MATLAB on the
non-homogenous network, IEEE-9 bus system and further tests are carried out on IEEE-39 bus
system in order to generalize and validate the efficiency of the proposed approach. The designed
trip boundaries are able to detect wide range of resistive faults under all TCSC modes of operations.
The proposed approach is easy to implement as there no need for data synchronization or a high
level of computation and filtration. Moreover, the proposed adaptive dynamic relay can be applied
for non-homogeneity systems and short as well as long TLs which are either TCSC-compensated or
-uncompensated TLs.

Thyristor controlled series compensation (TCSC) is widely used in long transmission lines to mainly improve power transfer capability. However, TCSC produces complicated impedance that negatively affects distance protection operation. The wind energy generation system produces additional complexity to the distance protection performance due to the variation of wind speed and fault current level. This paper proposes an integrated scheme to change adaptively the settings of the Mho distance protection by shifting the relay characteristics considering the bad impacts of TCSC, wind power and fault resistance. The proposed scheme achieves its main stages starting from fault detection, until relay tripping decision procedure including online estimation for preliminary fault location, impedance of TCSC and fault resistance using limited communication requirements. By extensive MATLAB simulations, the performance of the proposed scheme is examined compared with the conventional Mho relays under different fault locations, fault inception angle, fault resistance, different wind power penetration, different wind speeds and different TCSC ring angles. The achieved results ensured that the proposed scheme improves significantly Mho distance relay operation and avoids under-reaching and over-reaching problems irrespective of the large shunt capacitance along the transmission line, and also without identifying the parameters of TCSC such as the capacitance, the inductance or the ring angle.

Optimizing the Photovoltaic (PV) hosting capacity (HC) considering the irradiance’s variability properly and the load during the day represents a critical matter. Typically, the high PV HC results in overvoltage and high voltage fluctuations at the point of common coupling (PCC) with the utility. In this paper, a new algorithm is proposed for enhancing PV HC by considering the smart inverter functions to overcome key PCC issues. The Volt-Var and dynamic reactive current functions of the smart inverter are suggested to increase the PV HC. Furthermore, the time of use tariff is utilized for mitigating the duck curve issue at the utility by reducing the peak to valley difference of the substation net load curve. Quasi-static timeseries simulations are performed using the OpenDSS program to prove the effectiveness of the proposed algorithm. The proposed algorithm is validated by extensive numerical analysis on the standard IEEE 123 node test feeder. Deduced outcomes are very encouraging in mitigating the overvoltage, reducing the energy losses, limiting the considerable number of on-load tap changes, and alleviating the high voltage fluctuations.

Hybrid energy storage system has essential priority in Electric Vehicle applications. Therefore, the design of an appropriate power sharing algorithm among energy storage components is necessary to improve battery thermal performance and provide extra extension of battery lifetime cycles. This paper presents an analytical study on the effect of using wavelet decomposition-based power sharing algorithm to force the high frequency component to be fed by the supercapacitor and accordingly reduces the thermal stress on the battery. The proposed approach was investigated by applying it on electric vehicle model in ADVISOR Tool/MATLAB using different driving profiles such as Urban Dynamometer Driving Schedule profile, Highway Fuel Economy Test, New York City Cycle, Los Angeles 1992 and new European driving cycle. The results declare that by using proposed power sharing algorithm, the working temperature of lithium battery decreases significantly while battery lifetime cycles increase, apparently. For urban dynamometer driving schedule, the operating temperature of lithium battery is improved much at maximum decomposition levels reaching to only 25.6 °C compared to 35 °C. In addition, the battery lifetime cycles increased from 2213 to 2585 cycles. Neural Networks pattern recognition tool is also applied to classify the driving cycle to the nearest reference cycles chosen to represent the different driving conditions which help to detect the appropriate wavelet decomposition level, achieving better battery thermal performance and battery lifetime cycles.

The potential of electrifying Offshore Oil and Gas platforms by Hybrid Renewable Energy Sources (HRESs) was paid attention to recently. As sensitive loads, these installations require a high level of reliability, which requires special consideration in modeling. This load sensitivity contradicts the intermittent nature of HRESs like winds and waves. Implementing batteries in a similar energy system could help decrease the variation in the generated power. However, practical batteries are known to degrade over many factors. In this article, a study is presented on quantifying the enhancement in the reliability of supply caused by coupling of a Wind-Wave (WW) hybrid offshore energy converter (named: HOEC) unit with a Lithium-Based Energy Storage System (LBESS), while considering LBESS’s degradation and load sensitivity, and optimizing the battery size and WW ratios. The optimization is solved using a semi-analytical approach and compared against two heuristic algorithms, which are particle swarm optimization and pattern search algorithm. Results demonstrate possible system reliability enhancement while optimizing the system designed using the proposed approach.

Selectivity, reliability and security of electrical distribution systems are important issues in modern power systems. The protection coordination approach that depends on fault current only is no longer valid for medium voltage (MV) distribution systems; it has major limitations because of varying network conditions. In this paper, a new protective coordination technique is proposed in MV distribution networks. The proposed technique is based on calculating the rate of change of phasor voltage (ROCOV) in each feeder to discriminate and locate the faulty section. The measured ROCOV values and the required relay operating time take the shape of the standard inverse-time characteristics that are used for overcurrent relay. The system allows full coordination between the primary and backup relays. Without any need for communications, the proposed technique proved good robustness during different transient healthy conditions. The setting of the proposed relay does not need to be re-adjusted with the changes in network operating conditions since it depends on system voltage not the loading current. The proposed technique is tested using extensive MATLAB simulations under different faulty and healthy conditions in a MV distribution system. The results indicate that the proposed technique meets the fundamental protective requirements such as selectivity, reliability, sensitivity, and speed as well.

Portable devices are part of people’s daily lives, since they provide the capabilities that make life easier. However, they consume much energy that requires continuous charging. Integrating renewable energy sources, especially photovoltaic (PV) modules into wireless charging, has been widely adopted in order to increase availability, flexibility, safety, and robustness. In this paper, a new variable frequency control technique for inductive power transfer (IPT) is proposed in order to overcome the switching frequency limitation and increase the transfer efficiency without increasing the switching frequency. At first, charging power (PV power) is stored in a battery. Then, it is transferred based on inductive coupling when needed. The hardware of the proposed wireless charging system has been carried out for two different configurations. The first one is the single switch using a variable frequency control algorithm, which has achieved 40% efficiency. The other one uses half-wave inverter applying no resonance for two types of core: Nano-crystalline and ferrite. For that configuration, the maximum achieved efficiency has been 80% at zero air gap and 36.91% at the 5 mm air gap by the Nano-crystalline core.

The wide application of microgrid concept leads to challenges for the traditional protection
of distribution networks because of the changes in short circuit level and network topology during the two
modes of microgrid operation. This paper proposes a promising solution for these problems by offering
a new protection coordination scheme not affected by the variation of short circuit level or the changes
in network topology. The proposed protection scheme is based on local measurements at relay location
with low sampling frequency by computing the rate of change of fundamental voltage (ROCOV) to detect
different fault types, identify the faulty zone accurately and guarantee robust coordination between primary
and backup relays. The proposed coordination scheme can be achieved by optimizing either two settings for
relay characteristic (time dial setting and pickup value) or four settings (time dial setting, pickup and the
parameters that control the characteristic shape (A & B)). The proposed scheme is extensively tested using
MATLAB simulations on the modied IEEE 14 bus meshed network embedded with synchronous/inverter-
based distributed generation units under wide variations in operating conditions and short circuit levels
for both grid-connected and islanded modes of operation. The achieved results conrm that the proposed
coordination scheme can maintain the coordination between primary and backup relays for different fault
locations, types and different topologies. It provides selective, reliable, and secured microgrid operation
compared with conventional schemes, using fault current limiters and some other techniques discussed in
the literature.

Detection and location of open conductor in transmission systems using single-end data is a challenging task. This paper proposes a novel integrated scheme to detect and locate different types of open conductor faults (OCFs) in HV transmission systems. The proposed scheme unit (PSU) applies Discrete Wavelet Transform (DWT) with single-level decomposition on local current signals to detect OCFs correctly using adaptively estimated threshold values. PSU is also capable of dealing correctly with various normal transient conditions such as load capacitor switching. To ensure quick repair of OCFs, PSU captures the transient voltage surges and applies a fault location scheme using DWT and Clark Transformation to accurately estimate the location of different OCFs types. Extensive ATP simulations are employed to check the PSU performance under various OCFs conditions on a 345 kV, 100 km transmission line. The achieved results confirm the effectiveness, robustness, and reliability of PSU in detecting correctly OCFs as well as the low-impedance faults within only 1.25 cycles. Moreover, the percentage error in estimating OCFs location is less than 1%. PSU has also confirmed its capability to be applied in cascaded lines without any communication or synchronization between PSUs.

This article extensively investigates the calculations of the compensation factor of the thyristor-controlled series compensator (TCSC), which are used to accurately evaluate the negative impacts of the TCSC on the performance of conventional distance relays. To broadly evaluate the distance protection performance, the TCSC was adapted to the IEEE 9-bus system as one of the interconnected transmission networks that are increasingly spreading to improve service reliability, reduce reserve capacity, and enhance system efciency. In addition, IEEE 39-bus system, as a large interconnected system, is also examined to generalize the TCSC impact on different interconnected systems. To determine the precise impact, the impedance of the TCSC was calculated based on its practical design parameters. The impedance of the TCSC was examined as a function of transmission line impedance and ring angle. Both Mho and Quadrilateral distance relays were tested using the MATLAB/Simulink environment for different types of faults, fault locations, fault resistances, and ring angles for capacitive, inductive, and blocking modes of TCSC operation. In addition, distance relay performance was evaluated during power swing phenomenon in the presence of the TCSC. Simulation tests indicated the negative impacts of the TCSC on distance relay operation, which are not limited to over-reach and under-reach in faulty conditions but also to maloperation in dynamic disturbances that cause power swing phenomena on the protected line.

From about two decades passed, a new expression was proposed for the first time: ‘‘Virtual Power Plants (VPPs)”. At this moment, a question was asked about if the VPPs can contribute as a trustworthy and environmentally oriented energy supply, or not? From this instant, over two hundred articles was presented for the management and optimal utilization of such a system, reliability and adaptation of VPP with the network connected to, retail and wholesale markets . . . etc. Most or approximately all articles intended with VPPs focused on studying VPPs from economical point of view only and did not studied the electrical and energy performance of VPPs. This paper represents a novel combined model for economical and electrical performances together of a generic VPP (GVPP); the electro-economical model (EEM). Two main targets are required from the proposed GVPP EEM: best performance and active network energy management of this GVPP. Also, a proposal for the first real case study in Egypt is taken under consideration: Siwa Oasis, Egypt. Siwa Oasis proposed VPP is modeled also with EEM. EEM for these two cases (GVPP and Siwa Oasis VPP) are simulated to obtain best performance and active network energy management for these VPPs. All data and results are stated and discussed.