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Adding a damping unit to a shunt capacitor is an effective way to mitigate capacitor-caused resonance. However, damping units suffer from power loss issues. This shortcoming is amplified further in cases where resonance has a low possibility of occurring. In view of this, an adaptive damping method is proposed to improve the existing scheme. The damping unit is capable of mitigating resonance and eliminating the power loss under the non-resonance condition. The core idea of the proposed approach is to add a breaker so that the damping unit can be switched on or off depending on whether resonance occurs. The design of and control mechanism for the proposed switchable damping unit are presented. The performances of the new resonance mitigation scheme in terms of harmonic mitigation, loading, switching transient and cost are verified for an actual capacitor application case.

This paper introduces a smart coordinated allocation of distributed generation (DG) units, shunt-connected capacitors (SC), and static VAR compensators (SVC) for power loss minimization. The proble...

This article presents a new approach for solving the radial distribution systems optimal shunt capacitors’ placement and sizing problem. The approach modifies and partially uses the conventional loss sensitivity factors (LSFs) and MATLAB’s ismember and any commands to reduce the search space of optimal buses that require shunt capacitor placement. Afterward, the multiverse optimizer (MVO) is used to do a concurrent search of the most optimal buses and the corresponding capacitor sizes. To evaluate the effectiveness of the developed approach, simulations have been carried out on the 10-, 33-, and 69-bus radial distribution systems. For all the test systems, the simulation results show that the developed approach gives results as good as those obtained when a search for the most optimal buses is carried out in unreduced search spaces, hence making the approach effective in reducing the computation time and maintaining the much-needed accuracy. Finally, the performance of the MVO has been compared against the other 11 different optimization algorithms, and in all instances, its performance has been outstanding.

For a conventional islanded microgrid, each distributed generation (DG) unit usually equips with an LC filter and a closed-loop filter capacitor voltage control is applied to ensure an accurate tracking of DG voltage. In this article, a cost reduction microgrid and DG units configuration is developed via the following two steps. First, an L -type filter is adopted by each DG unit and a centralized shunt capacitor is placed at point of common coupling (PCC). Then, the inherent synchronization feature of droop control is further exploited as an inherent synchronizer to identify the carrier angle relationships between parallel inverters, but without any communications between them. With the carrier information obtained, a decentralized interleaving pulsewidth modulation (PWM) among parallel inverter can be easily achieved via a slow proportional integral (PI) regulation of each DG unit relative carrier. Accordingly, the high-frequency switching harmonics of PCC voltage are suppressed even with simplified and size reduced DG output chokes. Second, a virtual impedance control is applied to DG units to cancel the voltage drops on the DG feeder in a direct PWM manner. Accordingly, mitigating the low-order harmonic PCC voltages is obtained without using any closed-loop voltage tracking at DG unit local processor. Comparative experimental results have been provided to validate the correctness of the proposed method.

For multiple-receiver wireless power transfer (WPT), a scalable solution is desired that functions with changing number of receivers. Meanwhile, challenges lie in differences in load characteristics, power level, and cross coupling between the receivers. This article employs Class E $\bf ^2$ dc–dc converter topology for the multiple-receiver WPT systems working at megahertz (MHz). The shunt capacitor capacitances of the Class E rectifiers and magnitude of constant output current of the current-mode Class E power amplifier are chosen as design parameters aiming at decoupling the received power of each receiver. Design procedures are developed to simultaneously achieve high efficiency and desired individual load powers over a target variation range of the cross coupling. An experimental 6.78-MHz three-receiver WPT system is optimally designed. The system is shown to be capable of providing different target load powers (10, 8, and 6 W) and maintaining a high system efficiency (above 70%) with different combinations and positions of the receivers.

Capacitive power transfer is a promising mid-range wireless charging technique. The existing induced current source model suffers from the coupling variation issue, which causes troubles in resonance design and compensation development. This article explores an induced voltage source model for the capacitive coupler. Using this model, the six coupling-dependent capacitors between each pair of plates are equivalently represented by the self-capacitors and induced voltage sources. The self-capacitance is verified to be coupling independent. Based on this model, the power transfer capability, the efficiency, and the influence of adding external shunt capacitors are easily analyzed. This model is very helpful in investigating the existing topology and developing new compensations, such as the CLL-L compensation. Finally, a capacitive coupler is built to verify the model, based on which a CLL-L compensation is implemented for constant output voltage application. The achieved system peak efficiency is 88%.

Configuring a shunt capacitor as a detuned C-type filter is an effective way to mitigate the capacitor caused harmonic resonance. A design method has been developed recently that can guarantee the damping performance of the filter even if the system impedance data is not available. This article further improves the design method by considering the case where the system impedance data is available. It also answers the question if cost can be reduced by utilizing known system impedance data. For this purpose, the cost and power loss characteristics of the filter are investigated and included in the design. The performance of various design methods is compared from the perspectives of resonance-mitigation, power loss, cost, and robustness. The results have shown that the system independent design leads to superior performance except for the power loss. A guide on how to design the detuned C-type filter is recommended.

This work aims at reduction in active and reactive power loss reduction in distribution networks as well as to improve the voltage stability of the networks. Optimum Distributed Generation (DG) placement and sizing is carried out in conjunction with shunt capacitor placement and sizing to determine the appropriate sizes of DG units and Capacitor banks to be placed in the networks so as not to violate certain constraints. The optimal sizes of the DG units and capacitor banks were obtained on application of a Cuckoo Search Optimization Algorithm while computations for Voltage stability was performed using the Voltage Stability Index (VSI). The obtained optimal sizes of DG units and Capacitors were individually and simultaneously placed on the distribution networks to ascertain the behaviour of the networks prior to and after their placements. The performance factors considered are power loss and voltage stability. A comparison of these performance factors under separate and simultaneous placement method was demonstrated using IEEE 33 and 69 test buses. Result show that power loss (active and reactive) reduced by 63.29% and 59.38% respectively for 33 bus system, with a 74.29% and 79.19% reduction on 69 bus system. Voltage stability also increased by 7.89% and 3.79% respectively for 33 and 69 bus system relative to values obtained for base case and separate DG and shunt capacitor placement. Keywords: Distributed generation, shunt capacitor, Cuckoo Search Algorithm (CSA), power loss and voltage stability.

Recently, integration of distributed generations (DGs) and shunt capacitors in radial distribution network are becoming popular to withstand the rapidly increasing in electricity demands. In this a...

In this paper, an enhanced sitting–sizing scheme for shunt capacitors (4SCs) in a radial distribution system (RDS) based on an improved atom search optimization (IASO) algorithm is proposed. IASO emulates the model of atomic motion in nature based on interaction forces among atoms. The main goal of the 4SCs problem is to reduce the line losses and minimize the capacitor installation cost by searching for the optimal location and sizing of the capacitors. This leads to improvements in the voltage profile and reliability of the system. The IASO algorithm is introduced to achieve the optimal sitting and sizing of capacitors for RDSs. The proposed IASO algorithm is benchmarked and validated on different radial systems, including the IEEE 33-bus, IEEE 34-bus, IEEE 65-bus, IEEE 85-bus and Marsa Matrouh networks, to demonstrate its performance in real-world applications. The results obtained by the proposed IASO algorithm are compared with the standard ASO, PSO, SCA, GWO and SSA algorithms. Furthermore, the significance of the obtained results is confirmed by performing a nonparametric statistical test, i.e., the Wilcoxon’s rank-sum at the 5% significance level. The comprehensive results demonstrate that the results obtained by the proposed IASO algorithm denominate the results obtained by the other algorithms and that IASO minimizes the operating costs while achieving better voltage profiles.

In this brief, the analysis of mixed-element structures formed with shunt capacitors separated by commensurate transmission lines is performed first time in the literature. First, a low-pass lumped-element ladder network is considered. Then the series inductors are replaced with commensurate transmission lines. As a result, a practically important mixed-element structure is obtained. Then the description of the structure by means of two frequency variables (one for shunt capacitors and one for transmission lines) is detailed: Explicit expressions for the coefficients of the descriptive two-variable polynomials in terms of the coefficients of the single variable boundary polynomials are derived for various numbers of elements, which are obtained first time in the literature. Finally, a mixed-element broadband matching network is designed to illustrate the usage of the obtained expressions. If it is preferred not to have shunt capacitors, they can be replaced with open-ended stubs via Richard's transformation. So the resultant circuit is extremely suitable for microstrip fabrication. Kadir Has University

This paper introduces the load flow on the Egypt Electricity Network system. The effect of capacitor compensation has been studied from three points. First, the problem of the series capacitor compensation was considered. The second type of compensation considered is shunt compensation. Finally, a mixed of shunt and series capacitors compensation was implemented. The analysis results were discussed based on the maximum reduction in the generated MVAR. The load variation is accounted for by considering three different load levels classified as light, medium and peak load with pre-specified durations. When solving the capacitor placement problem, the number, size, location and control settings of the capacitors at different load levels were determined. The load flow program is solved by the Power World Simulator (PWS) software. The results of series capacitor, shunt capacitor, and mixed compensation were studied. The investigation has been done for single capacitor and multi-capacitor compensation. Both 500kV and 220kV overhead lines have been considered.

This paper investigates on minimizing the total network power losses using capacitor in Radial Distribution System (RDS). Fruit Fly Algorithm (FFA) is used for determining the sizing and Voltage Stability Index (VSI) is utilized to predetermine the location for capacitors. The present work is checked on standard IEEE 85-bus RDS. The outcome of the present approach is evaluated with the conventional methods. The result shows the developed method in identifying the optima sitting of shunt capacitor.

This paper demonstrates a wideband CMOS digital step attenuator (ATT) with high accuracy and low phase error working at 25GHz to 33GHz with 40nm CMOS technology. Shunt capacitors in the ground path are adopted for phase error compensation in bridged-T, T and π type ATT. The attenuation range is 15.5dB and the step is 0.5dB. The root-mean-square (RMS) attenuation error of the ATT can be less than 0.25dB and RMS phase error can be less than 1° under the whole bandwidth.

Device series connection is a method to achieve higher blocking voltage with multiple devices. However, a voltage unbalance among the series connected devices is a critical issue that may lead to a failure of the devices. The unbalance can be caused by difference of device characteristics and mismatch of gate signals due to delay of external gate drive circuit. In this work, a voltage balancing control (VBC) for series connected SiC MOSFET submodules is studied to solve the unbalance issue. One submodule consists of two switches and one shunt capacitor. By charging or discharging the shunt capacitor, voltage balancing can be achieved. The VBC is experimentally verified with four series connected SiC MOSFET submodules up to 3 kV DC voltage. Voltage balancing is achieved within 5 % of an expected balanced voltage.

In this article, a combined optimization approach (COA) based on Salp Swarm Algorithm (SSA) and loss sensitivity indices is proposed to determine the optimal allocation of shunt capacitors (SCs) in...

In the study, a coupled line trans-directional (CL-TRD) coupler that allows for equal complex termination impedances with arbitrary power divisions is presented. It is composed of two pairs of coupled lines with an overall electrical length of 90°, two types of shunt capacitors and three pairs of short-circuited stubs. By adjusting the electrical length of each short-circuited stub, as well as the values of the shunt capacitors, arbitrary equal complex termination impedances and power divisions are achieved. Moreover, since capacitors are shunted between the coupled lines, the proposed CL-TRD coupler has an inherent feature of dc blocking. Design equations for the CL-TRD were derived using even-odd mode decomposition analysis. To validate the theory, several numerical examples extracted from the design procedure were listed. Eventually, two prototypes of the proposed CL-TRD coupler are fabricated, and experiments are carried out. The measured results indicate that the coupler is able to realise arbitrary power divisions for equal complex termination impedance with good matching and isolation.

To enhance the UVC irradiation and prolong the life span of UV-lamps, parameter optimization is conducted for electronic ballasts. In this paper, the double capacitor topology is adopted and the effects of different ratios of shunt capacitors are investigated. Experiments are performed under different lamp power levels for each shunt capacitor ratio. The irradiance in each waveband emitted by the UV-lamp is measured using illuminometers and the variation trends are studied based on the excitation characteristics of mercury atoms. The effective lifetime of the UV-lamp is obtained through application tests, and it is verified to be remarkably prolonged when the double capacitor topology is adopted. Analyses and comparisons are discussed and an optimum shunt capacitor ratio is obtained, taking both increasing the UVC irradiation and prolonging the lifetime of the lamp into consideration.

Both active and reactive power play important roles in power system transmission and distribution networks. While active power does the useful work, reactive power supports the voltage that necessitates control from system reliability aspect as deviation of voltage from nominal range may lead to inadvertent operation and premature failure of system components. Reactive power flow must also be controlled in the system to maximize the amount of real power that can be transferred across the power transmitting media. This paper proposes an approach to simultaneously minimize the real power loss and the net reactive power flow in the system when reinforced with distributed generators (DGs) and shunt capacitors (SCs). With the suggested method, the system performance, reliability and loading capacity can be increased by reduction of losses. A multiobjective evolutionary algorithm based on decomposition (MOEA/D) is adopted to select optimal sizes and locations of DGs and SCs in large scale distribution networks with objectives being minimizing system real and reactive power losses. MOEA/D is the process of decomposition of a multiobjective optimization problem into a number of scalar optimization subproblems and optimizing those concurrently. Case studies with standard IEEE 33-bus, 69-bus, 119-bus distribution networks and a practical 83-bus distribution network are performed. Output results of MOEA/D method are compared with similar past studies and notable improvement is observed.

This paper addresses an incorporation of Distributed Generation (DG) and shunt capacitor in a distribution system simultaneously for minimizing active power loss. For this purpose, the Index Vector Method (IVM) and Power Loss Index (PLI) approach is utilized to determine the suitable position/location of DGs and shunt capacitors. However, the sizes/capacities of these are determined through population based Gbest-guided Artificial Bee Colony (GABC) meta-heuristic optimization algorithm. The various costs such as purchase active power from grid, DG installation, capacitor installation, DG Operation and Maintenance (O&M) are evaluated at two different load scenarios. In addition to that, technical and economical analyses are examined for various combinations of DGs and shunt capacitors. The proposed methodology is successfully demonstrated on 33-bus and 85-bus radial networks and the obtained numerical outcomes validate the suitability, importance and effectiveness to identify locations as well as sizes of DGs and shunt capacitors.

Distributed generation (DG) and shunt capacitors are widely adopted for minimizing power loss in distributed networks. But the high cost of DG units puts a limitation on employing higher rating DGs in distribution networks. So, it is desired that less DG size gives maximum loss reduction for achieving the objective of minimum overall cost of the system. The prominent goal of this paper is to curb the total expenditure occurring due to annual energy loss and cost incurred in installing DG units and capacitor banks. An unsullied methodical approach has been presented in this paper to find out optimal position and rating of DG as well as capacitor units so that the overall cost would be minimal. The method is tested on standard IEEE 69 bus distribution system and 130 bus Indian distribution systems. The outcomes of both the test systems are optimistic and found to be promising when compared with the previous ones.

High energy demands put ample load on power distribution systems which negatively impacts their performance. Excessive loading in distribution systems lead to more voltage drops, higher losses, and transformer/feeder overloads. As a low-cost solution, a capacitor bank can be installed to address these issues. However, their optimal size and location need to be determined in order to maximize its benefits. This paper proposes a voltage-to-load sensitivitybased strategy to find an optimal placement for the capacitor bank in a distribution network to reduce system active losses. Moreover, a feasible set of capacitor values is determined based on the system losses and voltage profiles. The proposed approach is tested on a test primary distribution system. The results prove the desired performance of the proposed approach.

Closing shunt capacitors is an effective way to adjust reactive power in 220kv substation and improve voltage quality. If the unintended input is frequently input, the inrush current will cause great impact on the power system and even damage the equipment. In order to reduce the inrush current of shunt capacitors, the mathematical model of the actual system closing shunt capacitor is established. The three-phase shunt capacitor closing strategy when the inrush current is minimum is calculated and the effectiveness of the closing strategy is verified. The mechanical switch closing is analyzed. The dispersion and voltage synchronization measurement error, the method of reducing the error is given and the closing delay is calculated to ensure that the parallel capacitor can be accurately closed at a specific time, and the influence of the shunt capacitor closing current on the power system is reduced.

In this paper, a new test circuit is proposed for overvoltage testing of capacitors based on a motor-driven regulating transformer. Motor drives tap selector which is designed to ensure good electrical contact and low wearing. Keeping the test circuit close to resonance requires lower power rating of regulating transformer. Test circuit is capable to generate overvoltage waveforms according to IEC 60871-1 without use of circuit breakers. A software was developed for evaluation of recorded overvoltage waveforms considering amplitude and time limits. The efficiency of test circuit is demonstrated on an actual overvoltage test performed on MV capacitor.

Frequent and sizeable voltage fluctuations become more pronounced with the increasing penetration of distributed renewable generation, and they considerably challenge distribution grids. Voltage regulation schemes so far have relied on either utility-owned devices (e.g., voltage transformers, and shunt capacitors), or more recently, smart power inverters that come with contemporary distributed generation units (e.g., photovoltaic systems, and wind turbines). Nonetheless, due to the distinct response times of those devices, as well as the discrete on-off commitment of capacitor units, joint control of both types of assets is challenging. In this context, a novel two-timescale voltage regulation scheme is developed here by coupling optimization with reinforcement learning advances. Shunt capacitors are configured on a slow timescale (e.g., daily basis) leveraging a deep reinforcement learning algorithm, while optimal setpoints of the power inverters are computed using a linearized distribution flow model on a fast timescale (e.g., every few seconds or minutes). Numerical experiments using a real-world 47-bus distribution feeder showcase the remarkable performance of the novel scheme.

This paper presents an efficient analytical technique to identify the optimal location and sizing of the distributed generation (DG) and shunt capacitor (SC) into a radial distribution system (RDS). The main objective of allocating DG and SC is to reduce the power losses which leads to improve the overall voltage profile with considering equality and inequality constraints. The DGs and SCs are placed at the bus that gives minimum power loss, while the optimal size is determined using the analytical technique. Moreover, a load variation with 50%, 100%, and 150% respected to the base case is studied to show the efficiency of proposed algorithm. Overall case studies are carried out using IEEE 69-bus RDS and the obtained results are compared with other optimization techniques used in the same manner.

Shunt Capacitor Bank (SCB) is usually preferred by power system design engineers for reactive power supports to run entire electrical network. SCB provides more flat distributed voltage profile, improves power factor of the system, reduces upstream current and hence line losses. Many times it can be configured as a “Harmonics Reduction Filter”. Hence there is need to provide protections to this ‘Heart of power system’ for keeping it present whenever you ‘Need it’. The proposed scheme provides unprecedented technic of capacitor switching differently from sequentially & time dependent In/Out of SCB to achieve target Power Factor as close as possible. The proposed system also provides relay based protection scheme for protection of over/under current, over/under voltage, current unbalancing with detecting number of elements failure & involved phase. The outage time management is done by remotely monitoring & controlling facility.

Power loss is considered as a major problem in any distribution network. This paper renders a solution by providing active and reactive power compensation through distributed generators (DGs) and shunt capacitors (SCs). Moreover, this compensation also improves the voltage profile along with the efficiency of the distribution network. Voltage Stability Index (VSI) is used to locate the compensating device at the appropriate location and the Modified firefly algorithm is used to calculate the appropriate size of the compensating devices. This compensation is implemented in IEEE 85-bus test system and the implemented results are compared with the previous studies and considerable improvement is observed.

This paper deals with algorithm for placement and sizing of the shunt capacitor banks in distribution networks of radial structure. In this paper algorithm for optimal placement and sizing of shunt capacitor banks is based on load flow calculation algorithm and integer genetic algorithm. Firstly, paper describes the problem of optimal placement and sizing of the shunt capacitor banks with constrains. Also, paper describes algorithm for the calculation of the load flow in the radial distribution networks. Used integer genetic algorithm is also presented. Proposed algorithm was verified on the IEEE 34 bus test distribution network. Finally, practical application of the proposed algorithm was demonstrated on one real 10 kV distribution network in Bosnia & Herzegovina.

The impact of penetration of distributed generation (DG) on shunt capacitor operation on a radial MV feeder with shunt compensation is assessed in this paper. Impact of capacitor location and DG location on the capacitor output and on feeder voltage profile in a network are both assessed and analyzed. South African utility capacitor placement methods are considered in studies. Two methods of calculating the feeder voltage profile are used in this study, where Method A is an approximate approach and Method B is a precise approach. Furthermore the accuracy of using Method A and Method B to assess the impact of DG on capacitors on an MV feeder is explored in comparison with results obtained from Power System Analysis (PSA) tools like DIgSILENT Powerfactory. The results inform the choice of using of Method A or Method B for the same analysis when PSA tools are not readily available. Studies are completed with DIgSILENT Powerfactory 2017.

To meet the increased load demand and improve the distribution network performance, it is necessary to use Distributed Generators (DGs) and shunt capacitors (SCs) simultaneously in the distribution network. In this paper, simultaneous allocation of distributed generators and shunt capacitors in the distribution system using flower pollination algorithm (FPA) is presented. The objectives are to reduce power loss and improve the voltage profile of the distribution system. The suitable nodes for DG and capacitor placement are identified by using the loss sensitivity factor (LSF) technique. FPA method determines the optimal size of the DGs and SCs. The method developed is studied on IEEE 33 bus test system and the results are compared with other methods.

This paper presents a novel analytical methodology to determine location for optimal shunt capacitor placement in power systems. The new method modifies modal analysis technique and develops new formulation to compute the Reactive Contribution Index (RCI) of each load buses based on the inversed reduced Jacobian matrix. The objective of this study is to achieve the most stable condition as well as to minimize network losses. The proposed method is implemented at the modified IEEE 30-bus Reliability Test System (RTS). The simulation results show the proposed method can provide a solution to the ideal shunt capacitor placement to improve the system's voltage stability.

This paper presents a new optimization algorithm, named intersect mutation differential evolution (IMDE) to optimally locate and to determine the size of DGs and capacitors in distribution networks simultaneously. The objective function is taken to minimize the power loss and loss expenses providing that the bus voltage and line current remain in their limits. Simulation results on IEEE 33-bus and 69-bus standard distribution systems show the efficiency and the superior performance of the proposed method when it is compared with other algorithms.

We have designed a low cost embedded device that would reduce the penalty billing of the consumers who fail to maintain the desired power factor.The analysis is made keeping in mind the concern for those bulk consumers of electricity (i.e. 11kV and downwards) in rural and sub-urban areas of India dealing varying load patterns.Switching of shunt capacitor banks though economical but often fail to give satisfactory compensation for varying load patterns. Hence combination of shunt capacitor banks intelligently would give a better solution to this problem. The present work focuses on the formulation of an optimization algorithm based on Ant Colony Search (ACS) technique operational from a Blackfin DSP microcontroller platform. This intelligent algorithm enables switching of appropriate Shunt Capacitor Banks (SCBs) in installations of bulk consumers of electricity to improve their power factor. The application is mainly targeted on cold storages, rolling mills, traction substation and steel plants in India, where SCBs are installed over a long period in an unplanned manner. Unawareness of the impact of energy savings coupled with the fiscal incapability of these users make them unable to install costly power electronic devices for p.f. control ACS based embedded controller is sensitive to unpredictable load changes and selective capacitors switching cause optimal VAR control with minimum stress to the system. Employing the distributed computational model based on ACS becomes an ideal tool for the combinatorial optimization problem to select a best combination within a bank of varying sizes and varying status signifying dynamically changing search space. This low cost device will reduce the penalty billing of consumers by improving the p.f. and improved metered reading. The use of this device will lead to permeation of technology to the strata which needs it most making energy management possible without any human intervention.

This paper presents a binary gravitational search algorithm (BGSA) is applied to solve the problem of optimal allotment of Shunt capacitors in radial distribution systems. In this work, total line loss (TLL) and the total voltage deviations (TVD) are to be minimized separately by incorporating optimal placement of shunt capacitors with constraints which include limits on voltage, sizes of installed capacitors. This BGSA is applied on the balanced IEEE 12-Bus distribution network and the results are compared with conventional binary particle swarm optimization (BPSO). --------------------------------------------------------------------***

This paper investigates the impact of distributed generation (DG) on the output of shunt capacitors using power system analysis (PSA) tool DIgSILENT Powerfactory. The study then investigates two non-PSA techniques and one alternative PSA technique which makes use of Load Flow Sensitivities (LFS) to perform voltage assessment and assess the effect of DG on medium voltage (MV) shunt capacitors. The use of non-PSA techniques is crucial to utilities in developing countries like those found in sub-Saharan Africa. Globally the use of PSA tools are part of standard practice and the use of LFS can be shown to reduce the steps involved in voltage analysis and provides additional benefit to using PSA tools. In this paper, authors use South African MV capacitor placement methodologies implemented by the national energy utility, Eskom.

This paper presents a novel technique for solving the simultaneous optimal distributed generators (DGs) and shunt capacitors (SCs) placement problem in order to minimize active power losses. A meta-heuristic Salp Swarm Algorithm (SSA) inspired from the swarming behavior of salps in oceans is implemented to determine optimal solution to this optimization problem. The proposed method is applied to 33 and 69- bus test systems. The obtained results have been compared with other existing methods, so that the comparisons confirm the performance as well as the effectiveness of the proposed method to determine the global optimum solution.

A half-wave Class DE low dvldt rectifier using common-grounded controlled shunt capacitor (CSC) is proposed. Since all switches are common-grounded, no high side gate driver is needed. In addition, using the proposed design approach, more number of outputs can be obtained than conventional design method. A prototype circuit with three CSCs was designed, analyzed, built, and experimented. In the experimental results, 12.1 V, 5.82 V, 3.81 V, 2.80 V, 1.72 V, 1.38 V, 1.14 V, and 0.956 V were obtained by variation of CSCs.

In this paper, we present a new configurable switched capacitor loading technique to achieve a shunt capacitor variable delay line with reduced capacitor area. Proposed delay line employs only two configurable and switchable capacitors to achieve the required delay value. Thermometer coded capacitors are utilized for linear and nondecreasing delay. The proposed architecture has high linearity figures with 0,0104 DNL & 0,0618 INL. The delay steps can be configured with 100 pS/step. Maximum delay range of the 10 cascaded delay cells is 10 nS. The delay cells can be activated separately to increase the control over the required delay range. The maximum operating frequency of a single delay cell is 90 MHz. The delay line architecture is designed in UMC 180 nm CMOS technology and simulation results are presented. The circuit operates with 1.8 V supply and the core delay cell consumes 95 mu W at 10 MHz PRF. The delay line with 10 cascaded delay cells consumes 536 mu W at 5 MHz PRF. Achieved linearity value of R-2 is 0,9999.

Parasitic inductance limits the high-frequency performance of surface mount capacitors in a shunt filtering configuration. This paper introduces a new compact design for cancelling this parasitic inductance that makes use of magnetic coupling between vias, as well as between coplanar traces. This design is intended for use on PCBs with more than two layers, and is an extension of the designs presented in the recent paper by the authors, “Parasitic Inductance Cancellation for Surface Mount Shunt Capacitor Filters.” Implementations of the new design are shown to exhibit similar filtering performance to comparable implementations of previously published designs, while requiring nearly 40% less board area. Additionally, implementations of the design are demonstrated to be effective in the practical situation of filtering the noise due to crosstalk on a four-layer board.

This paper presents an efficient hybrid method to solve the allocation problem of capacitor banks in radial distribution system (RDS). The presented method is based on two-stages. In the first stage, the most candidate locations for incorporating of shunt capacitors are determined using a loss sensitivity factor (LSF) and in second stage, the moth-flame optimization (MFO) algorithm is employed to determine the optimal sizes and locations of capacitors for to minimizing the energy cost. The presented method is validated using the standard 69-bus RDS under light, nominal and peak load levels. The obtained results using the proposed hybrid method are compared with those obtained from different reported optimization techniques in literature. Numerical results show the superiority of the proposed method over the other reported techniques for minimizing the cost in radial distribution system.

This paper presents a new optimization technique called Ant-lion optimization (ALO) in order to determine the optimal sitting and size of shunt capacitors in radial distribution systems (RDS). The objective functions are suggested to minimize the power loss and enhance the voltage profile individually or simultaneously. Standard IEEE 33-bus and 69-bus test system are used to validate the effectiveness and superiority of the new optimization algorithm compared with different well-known techniques. The obtained results demonstrate that both of power loss and voltage deviation can be minimized significantly after demining the optimal allocation of shunt capacitor banks using ALO algorithm.

The increasing penetration of electric vehicles (EVs) will bring great challenges to the secure and economic operation of distribution networks. On the other hand, coordinated charging of EVs can alleviate the adverse impacts of charging loads and even increase the efficiency of distribution network operation. This paper aims at optimally scheduling the daily charging of EVs and the daily on/off switching of shunt capacitors to minimize the total active power losses. We formulate a mixed integer second-order cone programming (MI- SOCP) model for this scheduling problem considering the distribution network security constraints. Case study results show that coordinated charging of EVs with reactive power optimization can effectively reduce the active power losses and improve the nodal voltage profiles.

Harmonic resonance has become an important concern for the application of shunt capacitors in recent years. A potential solution to address this challenge is to convert a shunt capacitor into a passive filter. This paper presents design methods to configure a shunt capacitor as a C-type filter or a third-order high-pass filter with guaranteed resonance-free performance. The concept of resonance-free condition is first introduced in this paper. It is then used to develop filter design methods that always meet the resonance-free condition. The two filter configurations are also compared. It was found that the third-order high-pass filter has more advantages than the C-type filter. Another useful finding of this work is that the filter parameters, as determined using the proposed design methods, are independent of the system conditions. As a result, a lookup table for the filter parameters has been created to facilitate immediate use by the industry.

In this paper, a novel analytical technique is proposed to determine the optimal size and location of shunt capacitor units in radial distribution systems. An objective function is formulated to reduce real power loss, to improve the voltage profile and to increase annual cost savings. A new constant, the Loss Sensitivity Constant (LSC), is proposed here. The value of LSC decides the location and size of candidate buses. The technique is demonstrated on an IEEE-33 bus system at different load levels and the 130-bus distribution system of Jamawa Ramgarh village, Jaipur city. The obtained results are compared with the latest optimization techniques to show the effectiveness and robustness of the proposed technique.

Power system stability is a serious concern of power system engineers and utilities especially after the recent occurrences of major events of black outs. Power factor improvement devices such as capacitors, optimally placed in series or shunt in any given network can improve its voltage as well as angular stability. Thermal limits of lines can be observed as the system is visible at all times through synchrophasor data. For this, New England 39 Bus system is used as test system. The simulations are carried out on PSSE. Compensation on selective buses is carried out using sensitivity analysis.

At present the use of distributed generation (DG) units and shunt capacitors simultaneously in radial distribution system (RDS) is very common to reduce losses and to improve the voltage profile in the system. Optimal location and size of DG and capacitors are crucial factors to maximize the loss reduction and to enhance the performance of the network. This paper, proposes an efficient hybrid method based on Genetic Algorithm (GA) and Artificial Bee Colony (ABC) which helps to determine the optimal location and size of DG sources and capacitor banks simultaneously. The main objective is to reduce real power loss in distribution system by placing multiple DG sources and capacitor banks. The proposed method is implemented on IEEE 33 and 69 bus radial distribution systems and results show the method is more effective than the results presented by other hybrid methods such as GA/PSO and ICA/GA.

Electricity has become a part of day to day life of the people. With the increase in population, electricity demand is also raised. The development of distribution systems (DSs), the optimal utilisation of shunt capacitor banks (SCBs) and distributed generators (DGs) in the DSs are heightened. In this paper, a methodology is proposed to allocate both DGs and SCBs simultaneously on the DS. The objectives are to minimise power loss, improving the voltage profile and voltage stability index (VSI) of the DS. First locations of DGs and SCBs are found out by loss sensitivity factor (LSF) technique. Next grasshopper optimisation algorithm (GOA) is used to determine the rating of these sources. The methodology is implemented on IEEE 33 and 69 bus test systems considering optimal allocation of multiple DGs without and with placement of capacitors. Finally, the results obtained by the proposed method are compared with GA/PSO and PSO methods.

To obtain the SaDE method, two enhancements have been employed on control parameters of crossover and mutation operators in original DE algorithm. To expands this discussion and shows the robustness of proposed algorithm, three load conditions have been considered, i.e., constant, varying and effective loads. Objective function is introduced for the load conditions. The annual cost is fitness of problem, in addition to this cost, CPU time, voltage profile, active power loss and total installed capacitor banks and their related costs have been used for comparisons.

Interruption of the direct current of a vacuum-arc discharge (VAD) is analyzed with three methods: the connection of a shunt circuit with a capacitor to the discharge chamber, the overlaying of a pulse nonhomogeneous axisymmetric magnetic field upon the discharge, and the combined action of the magnetic field and the shunt circuit. The probability of interruption of the current I = 500 A as a function of the magnetic field induction is obtained for various shunt capacitances within the range 25 ≤ C ≤ 2500 microfarad (μF). It is shown that the probability of interruption for a given magnetic field induction increases as the capacitance is raised and for the given capacitance it increases as the induction is increased. The magnitude of the magnetic system current I m to ensure the current interruption with the probability P = 1 is obtained as a function of the shunt capacitance. The impact of the shunt circuit parameters upon the arc current is analyzed. The time-domain plot of the arc current for the shunt capacitor C = 2500 μF was estimated. Its results agree with the experiment. It is shown that the combined use of the magnetic field and the capacitive shunt circuit is an effective method of VAD direct current interruption.