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Copyright of Zhejiang Electric Power is the property of Zhejiang Electric Power Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the case of resistance-inductance lines in PV station area, the problem of voltage overstep is easy to occur. This article proposes a reactive power compensation control method to improve the voltage stability in the photovoltaic power plant area, which addresses the problem of voltage at the point of common coupling (PCC) exceeding the upper limit due to resistance circuits and exceeding the lower limit due to relatively insufficient reactive power output when the output active power is high. The idea is to achieve dynamic adjustment of PCC voltage by paralleling a static reactive power generator (SVG) at the grid connection point and using a variable droop control method. In addition, a reactive power optimization method based on improved particle swarm optimization (IPSO) algorithm is proposed to address the changes in power flow caused by photovoltaic integration in the distribution network system. The proposed improvement method not only effectively reduces network losses but also significantly improves voltage stability. [ABSTRACT FROM AUTHOR]

Aiming at the problems of low equipment utilization and the high-capacity requirements of existing arc-suppression devices, a multi-functional reactive power compensation device with the capability of grounding fault regulation (MF-RPCD) is proposed. Firstly, the topology and operation mechanism of MF-RPCD are introduced in this paper. MF-RPCD works in a reactive power compensation mode when a power grid is under normal operation to ensure the unit power factor operation of the power-grid side. When a single line-to-ground fault occurs in the power grid, MF-RPCD works in a fault-regulation mode to effectively suppress the ground-fault current. Secondly, the parameters of the active and passive parts of MF-RPCD are optimally designed to ensure the stable operation of MF-RPCD. Finally, the correctness, feasibility and effectiveness of the proposed topology and functions are verified using simulations and experiments. [ABSTRACT FROM AUTHOR]

With the rapid development of high-voltage direct current (HVDC) transmission systems, the coupling between AC and DC grids is becoming increasingly close. Voltage disturbances in the grid can easily cause commutation failures in the DC system, threatening its safe and stable operation. The new generation of synchronous condensers (SCs) and modified synchronous condenser units are powerful reactive power support devices widely used in large-capacity DC transmission systems. To maximize the voltage support and commutation failure suppression of SCs, this paper proposes improvements in the initial operating state of SCs, using the Shanxi–Wuhan HVDC receiving end in the Hubei power grid as an example, to better support the HVDC commutation process. Additionally, a reactive power output optimization strategy for SCs is proposed, considering the reactive power equivalent factor of electrical connections between grid nodes. This strategy determines the optimal reactive power output limit of SCs near the converter station to suppress DC commutation failures. Simulation results show that this strategy effectively utilizes the dynamic support capabilities of SCs, prevents DC commutation failures, improves HVDC transmission capacity, and enhances the safety and stability of the receiving end power grid, providing theoretical guidance for reactive power output control. [ABSTRACT FROM AUTHOR]

Multi-functional photovoltaic (PV) inverters incorporate ancillary services to enhance power quality and mitigate stability issues in distribution networks. These next-generation PV inverters will achieve a higher utilization of the inverter's rated capacity, improving the cost-effectiveness of PV technology. However, the power required to perform ancillary services, such as load compensation capabilities, could exceed the inverter's capacity, risking the components' integrity. Therefore, multi-functional control algorithms must limit the power capacity according to the system's nominal currents. Despite this, most control proposals do not address this issue when load balancing capabilities are included for PV inverter control. This paper proposes a flexible control strategy for three-phase multi-functional PV inverters, considering load balancing functionalities while keeping the inverter currents within safe operating limits. The proposal introduces two control parameters whose variation results in different load compensation capabilities. These parameters can be adapted dynamically according to the inverter rated capacity not used for active power injection and the load compensation requirements. Additionally, a control algorithm is proposed to limit the inverter current according to the nominal values supported by the device. This algorithm also allows setting compensation objectives following a priority scheme in which the injection of the PV active power is prioritized over the load compensation functionalities. Reactive power compensation and load balancing functionalities are also considered at a lower level of hierarchical priority. The proposal was evaluated through experimental tests on a multi-functional PV inverter prototype under various operational conditions. The experimental results show an excellent control strategy performance, achieving the control objectives under unbalanced load conditions. [ABSTRACT FROM AUTHOR]

This work presents a novel grid integration scheme for a solar photo voltaic source through a distributed static shunt compensator (DSTATCOM). The proposed system used a Super Lift Luo Converter (SLLC) as an interface between the Solar Photo Voltaic (SPV) source and the DC link of the DSTATCOM. Two Proportional Integral converters were employed for the management of the real and reactive power transactions between the DSTATCOM and the point of common coupling (PCC). Since the grid integration of the harvested SPV energy was carried out by the DSTATCOM and the energy supplied through the SPV channel was unpredictable and varied over a wide range, the tuning of the PI controllers of the DSTATCOM became critical. The novelty of this paper lies in the fact that the two PI controllers of the DSTATCOM were tuned by means of the Gravitational Search Algorithm (GSA). The circuit model of the proposed system was developed in the MATLAB/ SIMULINK environment. Further on, a scaled-down experimental prototype of the proposed model was developed. The obtained simulation results showed that the proposed system which used the GSA for tuning the PI controllers outperformed the Particle Swarm Optimization (PSO) Algorithm and the Ziegler-Nichols based tuning technique. [ABSTRACT FROM AUTHOR]

Copyright of Urban Mass Transit is the property of Urban Mass Transit Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To address the issues of limited functionality and poor dynamic characteristics in traditional on-load tap changer transformers， this paper proposes a topological structure for a hybrid on-load tap changer transformer. This structure combines the efficiency and reliability of power-frequency transformers with the controllability of power electronic converters. By integrating back-to-back converters and designing corresponding control strategies， continuous voltage regulation and reactive power compensation for the on-load tap changer transformer are achieved. Additionally， the paper introduces a series voltage compensation method to provide fault protection for the load. Finally， an experimental model of the hybrid on-load tap changer transformer is built using MATLAB simulation software and an experimental platform. Both simulation and experimental results verify the correctness and effectiveness of the proposed topological structure and control strategy.

Objective Currently, the urban rail transit power supply system mainly relies on the main substation SVG (static var compensator) for reactive power compensation. During non-operating hours at night, the medium voltage loop network lines of urban rail transit power supply system are basically unloaded, and the charging reactive power of the lines is high, causing SVG to operate under heavy load for a long time. To alleviate the compensation pressure of SVG, a reactive power coordination control scheme for energy feedback device is proposed, coordinating SVG and the energy feedback devices in the traction substation to jointly participate in reactive power compensation. Method The calculation method of the energy feedback device reactive power compensation capacity is analyzed, and the reactive power coordination control strategy for the SVG and energy feedback device is proposed. Finally, on-site tests on a certain metro line are performed, verifying the correctness of the above strategy. Result & Conclusion When the energy feedback devices of a metro line are all put into use for reactive power compensation, the SVG reactive power compensation capacity can be reduced by 2.6 Mvar to the most, and the total active power loss of the me-dium voltage loop network line can be reduced from 0.7 MW to about 0.5 MW.

[Introduction] With the establishment of the energy Internet architecture mainly relying on new energies, HVDC transmission has become an important way of power transmission, power grids present a new characteristic of "strong DC and weak AC". Synchronous condensers have unique advantages in dealing with the issue of "strong DC and weak AC" by virtue of their dynamic performance such as fast reactive power response and strong voltage support capability. [Method] To study the application of synchronous condensers in HVDC works, this paper summarized the development of synchronous condensers, introduced the current development status of several major types of synchronous condensers in China, such as synchronous condensers for transforming thermal power units, new-generation large-capacity synchronous condensers, distributed synchronous condensers, analyzed the working principle and dynamic characteristics of synchronous condensers. Then the paper summarized the virtues of synchronous condensers when compared with other reactive power compensation devices such as SVC, the application scenarios, existing configuration strategies of large-capacity synchronous condensers and distributed synchronous condensers. [Result] Finally, a simulation model of DC transmission system with synchronous condensers is built on the PSCAD/EMTDC platform. The simulation verify the suppression capability of synchronous condensers for commutation failure at the sending end and transient overvoltage at the receiving end caused by commutation failure, as well as the dynamic reactive power compensation capability under lagging phase operation. [Conclusion] The analysis shows that synchronous condensers have adequate suppression of transient overvoltage and commutation failure and their reactive power response speed and dynamic reactive power support capability will not be affected by lagging phase operation, which contributes to their prospect of engineering application for steady-state compensation in converter stations.

AC submarine cable is an important component in AC transmission system of offshore wind farms. However, the issue of charging current limits its application in offshore wind power with long-distance and large-capacity. Taking HYJQF41-F290/500 kV single-core AC submarine cable as an example, the overvoltage distribution along the cable in different working conditions is analyzed, considering the long-distance and high-voltage transmission. The simulation model of the cable is established and its parameters are corrected firstly. According to the different compensation degrees of the shunt reactor, the capacity of the shunt reactor under the configuration scheme of single-end compensation and two-end compensation calculated out. Finally, based on the single-phase grounding fault, the closing and opening conditions in the high-voltage and long-distance wind farm models, and the distribution law of overvoltage along the submarine cable under different reactive power compensation schemes is tested by simulation. The results show that the maximum overvoltage of submarine cables appears in different positions with different compensation schemes. Based on this, the selection methods for high-voltage submarine cable and overvoltage in insulation level design of substation equipment are given out under different compensation schemes, which have certain guiding significance for engineering practice.

The paper studies the optimization features of low-voltage electrical network modes for energy-efficient power transmission. The main features of these networks are the high values of the zero-sequence voltage unbalance factor and the mismatch of voltage values with the necessary requirements. Therefore, balancing the loads by phases and reactive power compensation are chosen as measures to improve the listed network parameters. One of the main factors for the effective solution of this problem is the determination of load balancing points and reactive power compensation, as well as the required power of the devices used. To solve the multicriteria problem of determining device connection points, an analysis of existing objective functions is carried out. As a result, a target function is proposed that includes costs, voltage losses, zero-sequence voltage asymmetry coefficient. When solving the optimization problem with the help of the proposed objective function, the voltage values and the voltage asymmetry factor at the consumer connection points will be within the required limits. The results of a study of the optimization function using the example of a model network are presented. The calculations are carried out in two stages: the search for sensor's nodes, then their study for optimality. All calculations are carried out in the MATLAB environment, taking into account voltage losses and power.

This article presents an original methodology to determine the optimal level of reactive energy transmission to low-voltage consumers supplied from MV/LV substations that guarantees the lowest total costs of reactive energy transmission through the DSO network and its generation in receiving installations within the reactive power compensation process. The average value of the optimal factor tgφ to be maintained by customers depends on the efficiency of the network, the characteristics of the load, and the market costs of energy losses due to the transmission of reactive energy through the network that are covered by the DSO and the costs of reactive energy generation in receiving installations. The results presented for real MV/LV substations operating in the Polish distribution network demonstrate the application of annual measurements of active and reactive energy consumed and generated registered by AMI systems to calculate the optimal reactive power compensation level. They can be applied to verify the permissible levels of reactive energy compensation applied by the DSOs until now within the yearly tariffs for customers. [ABSTRACT FROM AUTHOR]

In industrial plants with dynamically varying load profiles, the problem of increased charges for over-contracted reactive power consumption is very common. To eliminate these charges, reactive power compensation systems are used. This article presents a case study of an automatic reactive power compensation system in an underground mine where a thyristor hoisting machine is used. To reduce the higher current harmonics of the hoisting machine and compensate for the reactive power of the PCC (Point of Common Coupling), the main reactive power automatic compensation system and an ASVG (Advanced Static Var Generator) with a nonstandard control loop were used. The article considers aspects of the operation of the ASVG, locally with the hoisting machine, and also as a master-controlled device that is part of the reactive power automatic compensation system. This part of the article is based on measurements taken in a mine. The reactive power automatic compensation system considered in this article has been successfully implemented, improving PQ (Power Quality) and eliminating additional overcompensation charges. [ABSTRACT FROM AUTHOR]

The burgeoning energy demands induced by modern civilization necessitate the procurement of additional electrical energy reserves to effectively address this escalating challenge. However, the installation of new power generation units necessitates building/upgrade of accompanying transmission infrastructure, a task fraught with complexities. To augment the loading capacity of existing transmission lines, power engineers have devised efficient solutions, one of which involves the integration of novel devices. This paper delves into the management of reactive power within vulnerable transmission networks, focusing particularly on the pivotal role of Flexible AC Transmission System (FACTS) devices. Among the diverse array of FACTS technologies engineered to fortify grid resilience, the Static Synchronous Compensator (STATCOM) which emerges as a transformative asset. The paper explores the integration of STATCOM within the 132 kV transmission network of the Diyala city ring power system to enhance its stability and operational efficiency. Simulations of the Diyala power network and load flow analysis were conducted using MATLAB/Simulink environment. The results unveiled a notable enhancement in power quality upon the integration of STATCOM, as compared to the base scenario devoid of such augmentation. These findings bear significant implications, offering valuable insights for the Iraqi grid operator and other nations grappling with analogous challenges pertaining to frail power networks. Incorporating such advanced devices into national electrical systems could potentially mitigate operational inefficiencies, defer infrastructure investment and bolster overall grid resilience. [ABSTRACT FROM AUTHOR]

Static Synchronous Compensator (STATCOM) is a self-tuning proportional-integral (PI) controller that has been developed to handle the voltage and reactive power of Cascaded H-Bridges (CHB-STATCOM) in order to improve the power system. The purpose of optimizing controller parameters for a Multilevel Converter-based STATCOM (Static Synchronous Compensator) in the context of reactive power compensation is to enhance the performance and efficiency of the STATCOM system in regulating the power factor and voltage of an electrical system. This controller was introduced in this article. This research presented that the STATCOM should have the capability to operate both in inductive and capacitive mode of operation and absorb or injects the desired amount of reactive power into the grid. The reactionary power that is received or supplied contributes to the improvement of the power system. The benefits of the self-tuning PI controller have been optimized to their full potential through the use of Accelerated Particle Swarm Optimization (APSO) strategies. The STATCOM is implemented into the electrical system, and its reaction to varying reactive and voltage levels is analyzed as part of the process of determining whether or not the optimization techniques are successful. Two controllers are now in operation at the STATCOM. The first controller is in charge of managing the DC voltage, and the second controller is in charge of controlling the reactive power. Both controllers are in use at the same time. The output of the controller is then transferred to the phase change carrier, which is followed by pulse width modulation in a sinusoidal pattern. Because of this, the power converter switch may now function properly. [ABSTRACT FROM AUTHOR]

Copyright of Electric Power Engineering Technology is the property of Editorial Department of Electric Power Engineering Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Southern Energy Construction is the property of Southern Energy Construction Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Summary: This article presents an improved least mean square (LMS) algorithm‐based control approach for a three‐phase grid interfaced solar photovoltaic (GISPV) system for smart building applications. The SPV is primarily utilized to supply household loads, and the absence or intermittency of SPV is curbed by utilizing power from the grid. The majority of household loads are nonlinear loads that affect the grid power quality (PQ). However, the effects of both linear and nonlinear loads on grid PQ have been analyzed in this article. This article proposes a Gaussian Kernel function‐based normalized LMS (GKNLMS) algorithm to calculate the active peak weight component of the load current, thereby utilizing it to obtain a sinusoidal reference current. Considering a higher step size and utilizing the Gaussian Kernel function for reduced mean square error (MSE) improves both the convergence rate and accuracy of estimation in the conventional LMS. The proposed control technique effectively addresses system anomalies caused by dynamic solar irradiance, load variation, and unbalanced loading conditions. Furthermore, the system response with the GKNLMS algorithm is assessed in MATLAB/Simulink and validated by developing a laboratory setup of the system for experimentation. [ABSTRACT FROM AUTHOR]

The influence of control discretization on the operation of semiconductor power regulators used in distribution networks for balancing operation mode and compensating reactive power is considered. Analytical expressions are presented for calculating the parameters of the power section of power regulators in two topologies. An analysis of the range of required parameters of the power section under continuous control is performed, highlighting the necessity of constraints considering practical implementation and control discretization. A method for assessing the efficiency of power regulators under discrete parameter control is proposed. An analysis of the impact of parameter setting discretization on the efficiency of operation of two power-regulator schemes is conducted. Various methods for calculating discrete values of the parameters of the power section of power regulators are discussed. The influence of calculation methods for power circuit parameters on the efficiency of power-regulator operation and the number of iterations required to calculate their discrete values is demonstrated. [ABSTRACT FROM AUTHOR]

A semiconductor reactive power controller with high-quality reactive current regulation and high technical and economic indicators is considered. The advantages of using switches based on thyristor switches as parts of reactive power compensators are shown. A semiconductor reactive power controller technology based on real-time control of an equivalent reactive element is presented. The use of a "binary" thyristor-switched capacitor group is considered as one of the most optimal power circuit implementations. Algorithms for active-adaptive control and high quality of network current and voltage, including reactive current control switching, are proposed. The block diagram of the device control system is considered, which ensures automatic maintenance of optimal network operating modes by updating the parameters of network digital mathematical twins and selecting the best operating mode of a semiconductor reactive power controller. The functional capabilities of the device are shown, allowing it to be integrated into modern active-adaptive electrical networks and digital substations. The operation results of pilot industrial samples are presented, confirming the effectiveness of the proposed technical solutions. The possibilities of scaling the technology in wide ranges of voltage and power classes are noted. The prospects for the development and application of devices are shown. [ABSTRACT FROM AUTHOR]

Copyright of Integrated Intelligent Energy is the property of Editorial Department of Integrated Intelligent Energy and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In the case of resistance-inductance lines in PV station area, the problem of voltage overstep is easy to occur. This article proposes a reactive power compensation control method to improve the voltage stability in the photovoltaic power plant area, which addresses the problem of voltage at the point of common coupling (PCC) exceeding the upper limit due to resistance circuits and exceeding the lower limit due to relatively insufficient reactive power output when the output active power is high. The idea is to achieve dynamic adjustment of PCC voltage by paralleling a static reactive power generator (SVG) at the grid connection point and using a variable droop control method. In addition, a reactive power optimization method based on improved particle swarm optimization (IPSO) algorithm is proposed to address the changes in power flow caused by photovoltaic integration in the distribution network system. The proposed improvement method not only effectively reduces network losses but also significantly improves voltage stability.

Virtual synchronous generator (VSG) enhances the stability of distributed power sources during grid connection by simulating the operating principle of a synchronous generator and introducing the virtual inertia and damping coefficient. However the traditional VSG control strategy struggles to address abrupt changes in grid voltage phase and amplitude when the voltage drops in the grid. Therefore, a low voltage ride-through control method for VSG based on phase and amplitude compensation is proposed. Firstly, the different effects of voltage drops and recovery on the power grid are analyzed. Secondly, during voltage drops, the purposes of overcurrent suppression, rapid stabilization of output power, and reactive power compensation are achieved by controlling the phase and amplitude difference between VSG output voltage and grid voltage within the allowable range. Then, during voltage recovery, rapid compensation eliminates the phase difference and amplitude difference between VSG output voltage and grid voltage to suppress overcurrent and other problems caused by grid voltage jumps. Finally, the effectiveness of the proposed control strategy is verified by MATLAB/Simulink simulation. The simulation results show that it can effectively suppress the overcurrent and realize reactive power compensation.

Line commutated converter based high voltage direct current (LCC-HVDC) is the key to large-scale grid connection and long-distance transmission of renewable energy. However, faults such as DC blocking and commutation failure may lead to short-term excess reactive power and transient overvoltage at the sending end, endangering operational safety. In this paper, a method based on grid-forming based reactive power compensation device (GFM-RPC) to suppress transient overvoltage at the renewable energy transmission terminal is proposed, which is different from the traditional reactive power compensation with the characteristic of current source based on voltage-current cascade control. A voltage dynamic analysis model based on differential-algebraic relationship is constructed to clarify the mechanism of GFM-RPC suppressing transient overvoltage, and the advantages of the proposed method compared to existing methods based on static synchronous compensator (STATCOM) for suppressing transient overvoltage is compared and analyzed. The simulation is used to verify the effect of GFM-RPC on the suppression of transient overvoltage at the renewable energy transmission terminal, and the influence of the main parameters on the overvoltage suppression effect is analyzed. It is shown that reactive power compensation devices such as STATCOM with external characteristics of current sources exhibit a reverse regulation characteristic of deteriorating voltage dynamics at the moment of DC transmission system fault, while the reverse regulation characteristic can be eliminated by GFM-RPC, as well as suppression of voltage magnitude overshoot can be achieved through reasonable parameter configuration for GFM-RPC.

Copyright of Electric Power Engineering Technology is the property of Editorial Department of Electric Power Engineering Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Reactive power compensation (RPC) is a big problem during power system operation. Parenthetically, capacitor allocation and sizing may be the only convenient solution for RPC of power systems. The loss sensitivity factor (LSF) is applied here for finding the optimum capacitor position. This paper presents quasi-oppositional fast convergence evolutionary programming (QOFCEP), fast convergence evolutionary programming (FCEP), and evolutionary programming (EP) for the optimum location and sizing of shunt capacitors in the isolated microgrid (MG) for minimizing total real power loss throughout the day with and without the demand response program (DRP). The 33-node, 69-node, and 118- node isolated MGs have been studied to authenticate the efficacy of the suggested approach. Each MG includes small hydro power plants (SHPPs), solar PV plants (SPVPs), wind turbine generators (WTGs), diesel generators (DGs), and plug-in electric vehicles (PEVs). [ABSTRACT FROM AUTHOR]

Copyright of Petroleum Refinery Engineering is the property of Petroleum Refinery Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Przegląd Elektrotechniczny is the property of Przeglad Elektrotechniczny and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Electric Power Engineering Technology is the property of Editorial Department of Electric Power Engineering Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In today's electrical distribution systems (EDS), the rise of renewable energy sources (RESs) and electric vehicles (EVs) holds immense significance. Despite their positive environmental impact, these technologies pose challenges due to their unpredictable nature. Efficiency and reliability are top priorities for EDSs, which can be achieved through optimal network reconfiguration (ONR). This approach addresses integrating varying RESs and EVs levels by considering distribution losses and the line loadability index (LLI). To enhance network performance by identifying optimal branches and tie-lines for switching, a novel meta-heuristic algorithm, the northern goshawk optimization algorithm (NGO), is proposed. To boost its search capabilities, an improved version, called improved NGO (INGO), introduces a levy flight distribution and an adaptive parameter. Simulations on unified Egyptian network (UEN) system across diverse scenarios demonstrate INGO's computational efficiency surpassing basic NGO and other algorithms like stochastic fractal search (SFS), harmony search algorithm (HAS), and artificial rabbits algorithm (ARO). INGO outperforms in target function optimization and computation time, showcasing its adaptability for real-time applications through reduced losses and enhanced loadability. In the initial network configuration, real power losses were measured at 805.73 kW and reactive power losses at 361.18 kVAr. Notably, the lowest voltage magnitude was recorded at bus-30, reaching 0.9463 p.u. The reliability index SAIDI was calculated as 3.148, corresponding to a maximum loadability of 1.73101 p.u. Following optimal reconfiguration with INGO, significant enhancements were observed. Losses reduced notably to 768.37 kW for real power and 360.86 kVAr for reactive power. The lowest voltage at bus-25 increased to 0.9511 p.u. Furthermore, SAIDI improved to 3.001, while loadability increased to 1.73903 p.u. These improvements were consistent even with varying PV and EV load penetrations. [ABSTRACT FROM AUTHOR]

Copyright of Large Electric Machine & Hydraulic Turbine is the property of Large Electric Machine & Hydraulic Turbine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Under the background of “double carbon”, the introduction of carbon trading and reactive power compensation mechanism in the planning of distributed generation is an important means to realize the low-carbon and stability of power system. Therefore, a optimal configuration method of distributed generation considering carbon trading and reactive power compensation was proposed. Firstly, the carbon trading mechanism was introduced to establish the calculation model of carbon trading cost. Then, a two-tier optimal configuration model of distributed generation considering carbon trading and reactive power compensation was established. The upper layer took the annual comprehensive cost as the optimization objective, and the decision variables were the location and capacity of photovoltaic and gas turbine connected to the distribution network. The lower layer took the system network loss, voltage offset and node voltage stability as the optimization objectives. The decision variables were the location and capacity of the reactive power compensation capacitor in the distribution network. Finally, the optimal configuration model was solved by the improved adaptive genetic algorithm. Combined with the example of IEEE33 node structure, the simulation analysis was carried out. The results show that the model can effectively reduce the loss of network and improve the stability of system voltage on the basis of ensuring the economy and environmental protection of the system.

In light of the growing prevalence of distributed energy resources, energy storage systems (ESs), and electric vehicles (EVs) at the residential scale, home energy management (HEM) systems have become instrumental in amplifying economic advantages for consumers. These systems traditionally prioritize curtailing active power consumption, often at an expense of overlooking reactive power. A significant imbalance between active and reactive power can detrimentally impact the power factor in the home-to-grid interface. This research presents an innovative strategy designed to optimize the performance of HEM systems, ensuring they not only meet financial and operational goals but also enhance the power factor. The approach involves the strategic operation of flexible loads, meticulous control of thermostatic load in line with user preferences, and precise determination of active and reactive power values for both ES and EV. This optimizes cost savings and augments the power factor. Recognizing the uncertainties in user behaviors, renewable energy generations, and external temperature fluctuations, our model employs a Markov decision process for depiction. Moreover, the research advances a model-free HEM system grounded in deep reinforcement learning, thereby offering a notable proficiency in handling the multifaceted nature of smart home settings and ensuring real-time optimal load scheduling. Comprehensive assessments using real-world datasets validate our approach. Notably, the proposed methodology can elevate the power factor from 0.44 to 0.9 and achieve a significant 31.5% reduction in electricity bills, while upholding consumer satisfaction.

This article addresses the optimality and stability issues of a Tidal power based hybrid power system (HPS). The Tidal system gets destabilized by the uncertain variation of tidal waves and wind input. Stability of the system is restored through the introduction of Unified Power Flow Controller (UPFC) controller. The controller is optimized through the process of configuration of Hyper Spherical Search (HSS) based algorithm. The evaluation of the effectiveness of the suggested controllers is conducted through comparison analyses in order to regulate the voltage profile of the interconnected power network under various loading scenarios. The efficacy of the suggested controllers is assessed by stability analysis utilizing Eigen and Nyquist plots. Further, it is quite evident that optimal tuning is possible in case of the controller where the parameters can create significant impact on the system performance. Consequently, a novel heuristic optimization technique, such as HSS Algorithm are suggested to find the best output of the proposed controller. Finally, by using real-data, the performance as well as robustness of the suggested controller have examined by utilizing a real-time digital simulation platform, specifically the OPAL-RT 5142.

With the integration of highly penetrative distributed photovoltaics into the distribution network, the imbalance between PV generation and load power becomes increasingly apparent, resulting in significant voltage security and stability issues in the distribution network. To overcome the limitations of traditional global voltage control and regional voltage cooperative control, a novel two-layer coordinated voltage control strategy, combining regional control and global control, is proposed for active distribution networks. Firstly, an adaptive partitioning of the active distribution network is achieved, without predefining the number of partitions, using the modular function gain change indicator and the Fast Unfolding algorithm. This adaptive partitioning ensures optimal regional control. Secondly, based on the voltage-power sensitivity principle, the reactive power control margin of PV sources is prioritized for regional-level reactive power control at critical nodes experiencing voltage violations. If the reactive power control margin within the region is insufficient, a combination of global-level reactive power control and active power control is employed. Lastly, simulation analysis is discussed by the IEEE 141-node traditional distribution network to confirm the effectiveness of the proposed method. Results demonstrate its ability to reduce the duration of voltage regulation and overcome the limitations of coordinated control range. The proposed method maximizes the utilization of the reactive power control margin of PV sources and significantly enhances PV penetration levels.

This paper presents an effective and practical structure to improve voltage and frequency regulation in grid-forming control of self-excited induction generator-based wind energy conversion systems. In the proposed control structure, in addition to a fixed parallel excitation capacitor, a small wound rotor synchronous generator is also used as a reactive power compensator. The excitation voltage of the small synchronous generator is controlled in such a way that by injecting the required amount of reactive power, this generator maintains the balance between the inductive and the capacitive reactive powers in the isolated system, and thus, improves the system voltage regulation. In addition, an active power control is proposed in which the speed of the prime mover of the self-excited squirrel cage induction generator is adjusted in such a way that the active power of the small synchronous generator is maintained at zero value. The proposed power controller, by creating the balance between the generated and the consumed active powers, improves the frequency regulation of the wind energy conversion system. The validity and effectiveness of the proposed structure are demonstrated through both simulation studies and experimental implementation. The obtained results confirm that the poor regulation of voltage and frequency, which is one of the major drawbacks of self-excited induction generator-based wind energy conversion systems, has been significantly mitigated by using the proposed method.

Aiming at the problems of low equipment utilization and the high-capacity requirements of existing arc-suppression devices, a multi-functional reactive power compensation device with the capability of grounding fault regulation (MF-RPCD) is proposed. Firstly, the topology and operation mechanism of MF-RPCD are introduced in this paper. MF-RPCD works in a reactive power compensation mode when a power grid is under normal operation to ensure the unit power factor operation of the power-grid side. When a single line-to-ground fault occurs in the power grid, MF-RPCD works in a fault-regulation mode to effectively suppress the ground-fault current. Secondly, the parameters of the active and passive parts of MF-RPCD are optimally designed to ensure the stable operation of MF-RPCD. Finally, the correctness, feasibility and effectiveness of the proposed topology and functions are verified using simulations and experiments.

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The objective of the presented paper is to verify economically justified levels of reactive energy compensation in the distribution network in the new market conditions, including the extensive use of smart metering systems, new types of load, or distributed generation. The proposed methodology is based on the minimization of annual costs of losses caused by the flow of reactive energy to the supplied loads through the equivalent resistance of the distribution system determined on the basis of statistical energy losses in this network. The costs of losses are compared to the costs of using compensating devices expressed by the levelized costs of reactive energy generation. The results are the relations describing the optimal annual average value of the tgφ factor to be maintained by customers to optimize the cost of loss of the distribution network caused by reactive energy flows. The dependence of the optimal tgφ value on the analyzed load and network parameters is also discussed. The resulting optimal tgφ levels should be considered in the tariffication process of services offered by distribution system operators to improve capacity and limit the costs of power network operation due to reactive energy transmission. [ABSTRACT FROM AUTHOR]

This paper presents a case study in which the influence of the 6-pulse thyristor-bridge input reactor size on the shunt active power filter (SAPF)'s work performance is investigated. The purpose of using an SAPF in the power system is in most cases for fundamental harmonic reactive power compensation, harmonics and asymmetry mitigation. The work efficiency of such a filter depends not only on the designed control system, interface filter and dc-link capacitor parameters, but also on the parameters of the electrical system in which it is connected. Therefore, it is necessary to study and know the power system (supplier and consumer sides) before its installation. For instance, in the electrical system with diode or thyristor-bridge as loads, the SAPF performance efficiency may not be satisfied due to the high rate of current change (di/dt) at the points of commutation notches. In this paper, the performed simulation and laboratory experiments show that for a better operating efficiency of the SAPF, the input reactor parameters should be selected based not only on the effective reduction in the inverter switching ripple or the control system demand, but also on the parameters of the load, such as the parameters of the diode or thyristor-bridge input reactor. Apart from the experimental demonstrations on how the input reactor size influences the SAPF work efficiency, the novelties in this paper are: the formulated recommendations on how to choose the SAPF input reactor parameters (the SAPF is more efficient in terms of harmonics, asymmetry and reactive power mitigation when the inductance of its input reactor (L-filter) is smaller than the one of the diode or thyristor-bridge input reactor); the proposed SAPF control system; the proposed expressions to compute the SAPF input reactor inductance, DC voltage and capacitor. [ABSTRACT FROM AUTHOR]

Many countries have benefited from industrialisation and there is a growing global demand for power. For a power system to operate steadily, securely, and dependably, infrastructure must be upgraded and supply and demand must be balanced. In particular, reactive power (VAr) compensation is crucial for balancing the demand for reactive power from industries and, as a result, to ensure a sufficient voltage profile and voltage stability in low-voltage distribution lines. This study suggests the use of switched and fixed capacitors for dynamic volt-var controllers to handle heavy industrial loads. The voltage stability improvement, cost reduction, and loss reduction are the three goals of the multi-objective function. a new, straightforward meta-heuristic for war strategy optimisation (WSO) that combines the power loss index (PLI) to narrow the search space and boost the computing effectiveness. For various industrial load growth scenarios, simulations were performed on IEEE 33-bus low-voltage distribution feeder. A comparative study was also conducted using and compared with WOS (i.e., without reduced search space with PLIs) and whale optimization algorithm (WOA). In terms of global optima, the PLI-WSO findings are superior. In basic 33-bus feeder, having 84.78% VAr compensation results in a 34.39 % loss reduction and 33.23 % cost reduction in a 33-bus feeder, whereas having maximum 16% of industrial load growth in 10 years, the losses and costs are increased by 24.41 times to the base case, respectively. However, by having optimal VAr compensation, the losses and cost savings are resulted for 8.627% and 8.404%, respectively. Different load increase scenarios showed a similar type of overall benefit, demonstrating the scalability of the suggested methodology for real-time larger systems. [ABSTRACT FROM AUTHOR]

This paper presents a detailed study on the analysis of the reactive power compensation methodology used for delivering the maximum power to single-phase grid–PV systems. The main purpose of this work is to develop a Sunflower Optimization (SFO) integrated with a Self-tuned Fuzzy Logic Controller (SFLC)-based Maximum Peak Point Tracking (MPPT) controlling mechanism for extracting the maximum power from the solar PV system. For this, an efficient Entwined LUO (ELUO) DC-DC converter has been utilized that helps to regulate the output voltage with reduced ripples. Also, the inverter provides real power in addition to the reactive power without exceeding its current limit. For controlling the capability of energy transmission, the Phased Locked Loop (PLL) based synchronization is performed at the point of common coupling. Additionally, the LCL filtering technique is employed to reduce the harmonics and unbalanced current efficiently. The proposed system improves the overall system performance by producing grid-side current in a clean sinusoidal shape with an appropriate phase shift in grid voltage. The simulation and experimental results are validated to demonstrate the effectiveness of the proposed control method. [ABSTRACT FROM AUTHOR]

In this paper, a control algorithm is proposed for a multifunctional inverter to improve power quality in a grid-tied solar photo voltaic (SPV) systems connected to non-linear and unbalanced loads. During light loads and low solar irradiance, the surplus capacity of inverter rating is optimally utilized to compensate some of the power quality (PQ) indices based on conservative power theory (CPT) along with active power injected into the utility grid and also connected loads. The stationary reference frame based proportional resonant (PR) current controller is designed to facilitate accurate tracking of inverter currents, fast time response under dynamic conditions when unbalanced and non-linear loads are connected at the point of common connection (PCC). The proposed control scheme enables selective compensation of power quality indices such as harmonics, unbalance and reactive powers depending on type of load and grid requirements there by, reducing the burden on the utility grid. Experimental results for various dynamic conditions are presented to validate the proposed controller performance and highlight the merits. [ABSTRACT FROM AUTHOR]