Active Power Line Conditioner Research Articles

Receiving-End Voltage Compensation Method with NPC-Inverter-Based Active Power Line Conditioner in Three-Phase Four-Wire Distribution Feeder

This study proposes a receiving-end voltage compensation method employing a phase-specific reactive power control strategy with a neutral-point-clamped (NPC) inverter in a three-phase four-wire distribution system. The principle of the proposed receiving end voltage compensation method is explained. Further, the proposed control strategy can solve the problems of the three-phase, four-wire distribution system, which are an increase in the neutral-line current and the unbalanced voltage. Computer simulation is performed to confirm the validity of the proposed method. The simulation results indicate the receiving-end voltages can be compensated using the proposed method.

Assessment of unbalance and distortion in power systems that include active power line conditioners.

This paper presents a decomposition of the apparent power of a system that allows to separate the contribution to the unbalance of the whole set of harmonics of voltages and currents. From this set of power terms, the unbalanced fundamental, balanced harmonics and unbalanced harmonic indices are derived, that allow to evaluate separately the distortion and the unbalance. This procedure gives a more appropriate way to characterize the mitigation obtained using modern equipments with active compensation. These new indicators of the electric power quality have been applied here to a system with unbalance and distortion in the supply and the load, before and after the connection of a parallel active compensator, and with the connection of a series-parallel active compensator. The results obtained with a dedicated experimental platform have allowed to verify the validity of the new proposed indices.

OPTIMAL PLACEMENT AND RATING OF CUSTOM POWER DEVICES IN 15-BUS SYSTEM FOR POWER QUALITY IMPROMENT WITH STATIC SYNCHRONOUS COMPENSATORS (STATCOMs) AND ACTIVE LINE POWER CONDTIONER

This paper presents on power quality improvement in distributed radial network by using custom power device (CPD). In power system, the power quality issue become more complex at all level. Here, for this concern, we introduce a concept of custom power, basically it is a power electronics controller, to provide a quality of power to the supplier as much as for consumers. Custom power device (CPD) including active power line conditioner (APLC) and static synchronous compensators (STATCOMs), simulating on modified distributed IEEE-15 bus distorted bus system with the help of MATLAB Simulink software to explore performance and the efficiency of each device under various quality (power)disturbances includes voltage swell and sag, interruption in power and total harmonics distortion as well as the performances of allocated CPD in control the voltage quality and reactive power. Here, we used the particle swarm optimization to determine optimal location and sizes of CPD. Here, simulation results reveal all the effect of each device to compensate several types of power quality disturbance depends on the devices configurations and in this paper we much emphasized on STATCOMs and its arrangement.

A novel multi-objective framework for harmonic power market including plug-in electric vehicles as harmonic compensators using a new hybrid gray wolf-whale-differential evolution optimization

Plug-in electric vehicles are capable of providing harmonic reference currents to the smart micro-grid in order to approximately neutralize the undesirable effects of the harmonic sources. This paper proposes a holistic multi-objective optimization framework for plug-in electric vehicles' involvement in accurately clearing the harmonic power market in a micro-grid. The proposed multi-objective framework is capable of concurrently optimizing contradict objectives, comprising total distortion payment function of the harmonic compensators, and mean of total harmonic distortion while satisfying the constraints associated with the network, vehicles, and market price. The payment function includes availability, loss, and loss of opportunity cost terms according to the harmonic capability curve of the plug-in electric vehicles and active power line conditioners. Moreover, this study proposes a novel hybrid algorithm consisting of the whale optimization, the gray wolf optimization, and the differential evolution algorithm for settling this new market framework. The best compromise solution is selected based on a particular preference among diverse Pareto optimal solutions on a fuzzy decision-making procedure basis. In order to illustrate the effectiveness of the proposed methodology and the outperformance of the plug-in electric vehicles compared with the active power line conditioners, the single-objective and the multi-objective harmonic power market under different circumstances are employed in this study.

A New Optimization Framework for Harmonic Compensation Considering Plug‐in Electric Vehicle Penetration Using Adaptive Particularly Tunable Fuzzy Chaotic Particle Swarm Optimization

Plug‐in electric vehicles (PEVs) can contribute to eliminating undesirable harmonics generated by nonlinear loads. In this study, a novel stochastic optimization approach for harmonic compensation is proposed which is capable of optimizing contrary objectives, including total harmonic distortion and harmonic inject current, simultaneously, while meeting the relevant constraints. This problem can be influenced by the uncertainty of PEVs which is reflected in the force outage rate concept. The Monte–Carlo simulation technique is implemented to consider the uncertainty associated with PEVs by generating plausible scenarios with the aim of converting the mentioned framework to the respective deterministic equivalents. Afterward, adaptive particularly tunable fuzzy chaotic particle swarm optimization (APTFCPSO) is utilized, based on the weighted sum method, and the acquired results are compared with those obtained by other implemented swarm intelligence‐based algorithms. Accordingly, at first, several benchmark optimization functions are considered to verify the performance of the APTFCPSO. Afterward, active power line conditioners (APLCs) and PEVs are separately employed for harmonics cancellation in the deterministic form. After adopting the scenario reduction technique, the optimization framework is solved for each remaining scenario by the mentioned procedure. The statistical analysis reveals that PEVs outperform APLCs to cancel harmonic orders defined in a 14‐node micro‐grid.

Scenario-based stochastic framework for harmonic power markets using plug-in electric vehicles

With respect to growing the nonlinear loads, it is appealing to employ Plug-in electric vehicles (PEVs) as harmonic compensators to distributedly mitigate harmonic pollution. Hence, this study is intended to propose a comprehensive stochastic optimization framework for PEVs participation considering their uncertainties to accurately settling harmonic power market by distribution system operators. The optimization framework consists of the total expected distortion payment function (DTPF) of the accepted harmonic compensators, such as PEVs and active power line conditioners (APLCs) as an objective function while fulfilling the constraints concerned with the grid, vehicle, and market price. The DTPF comprises availability, loss, and loss of opportunity cost terms based on the harmonic capability curve of the harmonic compensators. Furthermore, the Monte-Carlo simulation based on the contingency concept is utilized to generate scenarios for covering the uncertainties of the PEVs, and then the scenarios solve by adaptive particular tunable fuzzy particle swarm method. This study demonstrates the efficiency of the proposed framework and the outperformance of the PEVs compared with APLCs investigated on a 14-node microgrid.

Harmonics Compensation in Three-Phase Four-Wire Distribution Feeders With a Four-Leg Structured Active Power-Line Conditioner

Harmonics Compensation in Three-Phase Four-Wire Distribution Feeders With a Four-Leg Structured Active Power-Line Conditioner

Single-phase power line conditioning with unity power factor under distorted utility voltage

The paper proposes a control method of a single-phase active power line conditioner (APLC) aimed at correcting the power factor of linear and non-linear loads supplied by distorted voltage utility. The method, that is based on the single-phase p-q theory and utilizes a third-order sinusoidal signal integrator, gets utility unity power factor and, at the same time, overcomes the shortcomings of the solutions pursuing utility sinusoidal current, namely the possible onset of un-damped resonance phenomena and the reduction in the energy delivery capabilities; moreover, the method makes the power factor correction robust against the supply distortion. The excellent performance of the method is substantiated by testing it by means of a hardware-in-the-loop setup.

Comparative Performance Analysis Involving a Three-Phase UPQC Operating With Conventional and Dual/Inverted Power-Line Conditioning Strategies

This article deals with a complete evaluating and comparative analysis involving static and dynamic performances of a three-phase unified power quality conditioner (UPQC) controlled to operate using conventional and dual/inverted compensation strategies for performing active power-line conditioning. In the conventional strategy, the series converter of the UPQC operates as a nonsinusoidal voltage source, while the parallel converter operates as a nonsinusoidal current source. Differently, when the UPQC operates with a dual/inverted strategy, the series converter operates as a sinusoidal current source, while the parallel converter is controlled to act as a sinusoidal voltage source. Although, in theory, the results achieved using the mentioned strategies looks similar, in practical applications there are considerable differences in both static and dynamic performances that must be considered for choosing the best compensation strategy to be adopted. Thus, this article addresses aspects related to the mathematical modeling, control and generation of the control references applied to the UPQC, which are implemented using two three-level neutral-point clamped inverters. Furthermore, the performance of the UPQC operating under static disturbances (grid voltage harmonics/unbalances and load current harmonics), as well as dynamic disturbances (voltage sags/swells and load changes) are extensively tested by means of an experimental setup.

Power Flow and Stability Analyses of a Multifunctional Distributed Generation System Integrating a Photovoltaic System With Unified Power Quality Conditioner

This paper presents detailed studies involving sizing, stability analysis, and power flow through the series and parallel power converters in a multifunctional three-phase distributed generation (DG) system composed of a single-stage photovoltaic (PV) system integrated into a unified power quality conditioner (UPQC). The UPQC operates as a bidirectional interface when the DG system is placed between the grid and either generic loads or ac microgrid. In the grid-connected mode, the DG system performs active power-line conditioning, while injecting the energy produced by the PV array into the grid. In islanded operation, the system can act as ac grid forming via a parallel inverter, whether there is the presence of an energy storage system. A complete study involving the power flow through the PV-UPQC is mandatory to achieve the overall understanding of the system operation and designing the power converters properly. For this purpose, sizing curves are presented and discussed. Furthermore, two strategies aimed at limiting and/or decreasing the power processed by the series and parallel inverters are presented and discussed in detail. Both simulation and experimental results are presented to evaluate the static and dynamic performances of the PV-UPQC system operating grid connected and grid islanded.

A harmonic power market framework for compensation management of DER based active power filters in microgrids

Harmonic distortions are going to be more important in the near future due to widespread employing of power electronic based devices. The quality of power may get degraded without using proper mitigation methods. On the other hand, new paradigms of deregulated markets which make the power a competitive product as well as customer inclinations to pay for a high-quality power, inspire distribution companies to enhance the power quality level. Hence, various investigations should be considered to meet the power quality standards in electric networks. In this paper, a market-based framework is proposed for central management of harmonic compensation actions in microgrids (MGs). Since distributed energy resources (DERs) are prevalent in MGs, the compensations actions could be based on DERs activities in addition to conventional active power line conditioners (APLCs). Hence, a detailed investigation of harmonic filtering capabilities of various DERs is firstly represented. Afterward, a global model is proposed for various harmonic active power filters (APFs) either based on DERs or APLCs. To comply with the obligations of deregulated power markets, a new concept named as harmonic power market (HPM) is proposed for economic management of various APF resources participating in harmonic mitigation actions. Furthermore, a distortion power expexted payment function (DEPF) is introduced for each APF participating in the HPM. The HPM framework is modeled as an optimization model subject to various standards, technical and systematic constraints implemented in some case studies. Simulation results show the capability and performance of the proposed model for optimal management of various APF resources in harmonic compensation. Increasing in harmonic filtering capability, deferring the requirements for installation of new APLCs as well as a decrease in harmonic compensation costs are the main advantages of using DER based APFs in the HPM.

Dynamic performance comparison involving grid‐connected PV systems operating with active power‐line conditioning and subjected to sudden solar irradiation changes

This study presents a comparative performance analysis involving single- and double-stage photovoltaic (PV) systems, which are connected to a three-phase four-wire electrical system by means of a four-leg inverter topology. The double-stage PV system is composed of a step-up DC/DC converter and a four-leg grid-connected inverter, while in the single-stage PV system the PV array is directly connected to the inverter DC bus. In addition to the active power injection into the grid, both PV systems have two attractive features, described as follows: (i) power quality improvement due to their capability to perform active power-line conditioning, such as load harmonic current suppression, reactive power compensation, and load unbalance compensation; (ii) dynamic improvement in the occurrence of abrupt solar irradiation variations, which is achieved through the implementation of a feed-forward control loop (FFCL) acting directly in the inverter DC-bus voltage control loop, resulting in speeding up of the dynamics of both the DC-bus voltage and the injected grid-inverter currents. The referred comparative analysis addresses the static and dynamic performances considering the PV systems operating under the action of the FFCL, as well as performing active power-line conditioning. Simulation and experimental results are presented to evaluate and validate the proposed study.

Optimal Sizing, Siting and Operation of Custom Power Devices With STATCOM and APLC Functions for Real-Time Reactive Power and Network Voltage Quality Control of Smart Grid

A new custom power device (CPD) is introduced for real-time control of reactive power and improving the overall network voltage quality of smart grid (SG) at fundamental and harmonic frequencies, respectively. The idea is to take advantage of the online smart meter data transmitted from each bus to the SG central control to concurrently perform the static synchronous compensator and the active power line conditioner operations by optimal compensations of fundamental reactive power and harmonic currents at selected optimal buses. The proposed strategy involves two particle swarm optimization algorithms. The first algorithm is implemented for the worse operating condition to determine the optimal locations and sizes of CPDs while the second algorithm relies on smart meter information to continuously compute fundamental and harmonic reference currents for real-time operation and control of the allocated CPDs. The objective functions are cost minimizations associated with bus voltage regulations, network total harmonic distortions voltage and custom device sizing while the constraints include upper limits for CPD sizes, fundamental, and harmonic bus voltages. Detailed simulations are performed in MATLAB/Simulink to evaluate the performances of allocated CPDs in controlling the reactive power and voltage quality of a distorted 15-bus SG with six nonlinear loads according to the IEEE-519 standard.

Interval Type-2 Fuzzy Logic Controller-Based Multi-level Shunt Active Power Line Conditioner for Harmonic Mitigation

The use of variable speed drives in industries introduces harmonics that should be attenuated so as to improve the power quality. To overcome the shortcomings of the traditional passive filters in electric power system, shunt active power line conditioners (APLC) are employed. The regulation of DC capacitor voltage plays a vital role in deciding the performance of shunt APLC. Several intelligent controllers have been developed for the voltage control; however, due to high uncertainties associated with the electric power system, an interval type-2 fuzzy logic controller (IT2 FLC) is proposed. This work compares IT2 FLC, type-1 fuzzy-tuned proportional integral (PI) controller, and their performances are assessed with reference to conventional PI controller using MATLAB. Thus, the paper deals with the investigation of three-level Multi-Level Inverter which is used as shunt APLC in high-power applications using a fuzzy logic scheme.

Active Power Line Conditioner with Impulse Asymmetric Current Battery Charging System

A scheme of an active power line conditioner with a battery charge system with impulse asymmetric current battery charging system is presented. Numerous publications point to the expediency of constructing a system that would realize both functions of compensation of reactive power and the provision of guaranteed power supply. The existing nonlinearity of loads affects the reduction of the power factor and the increase of the content of higher harmonics of consumpted current, which leads to distortion of form of network voltage. Many loads require high quality power supply, and their high-quality work can only be achieved with low content of higher harmonics and a shape factor that corresponds to the ideal sinusoidal voltage. In addition, the deviation of the power factor from one and the corresponding current distortion result in energy losses in the networks and equipment, which in turn is one of the reasons for additional heating and a decrease in the life of the devices. From the analysis of battery charge methods, it follows that the method of impulse asymmetric current battery charging exceeds the quality of the other and provides a reduction in the charge: the memory effect, peak values of temperature and internal pressure of the battery, which can increase the life of the battery in 1.5-3 times. The main disadvantage of this method of battery charge is a relatively low efficiency, but with the use of circuit solutions that allow using the energy of a bit pulse repeatedly to charge the battery, the efficiency is increased to 80-90% and above. Total increase in the efficiency compared with existing devices reaches 12-34%. The purpose of the work is to calculate the reactive elements and the main parameters of the filter-compensating converter when used together with the system for the sake of the battery with impulse asymmetric current. Time diagrams describing the main operating modes of the device, as well as equivalent circuits of the converter, that describes its operation at the appropriate time intervals are given. Using the balance of energy and the method of calculation on average currents and voltages, expressions for calculating the basic parameters of the compensator, provided the consumed additional energy for charging the battery are derived. It is determined that the capacity of the storage capacitor increases in proportion to the additional energy required to charge the battery, with the constant value of the inductance of the smoothing inductor.Ref. 10, fig. 3, tabl. 1.

Optimal allocation of plug‐in electric vehicle capacity to produce active, reactive and distorted powers using differential evolution based artificial bee colony algorithm

Plug-in electric vehicles (PEVs) can produce active, reactive and distorted power as well as pollution reduction. This study proposes an optimisation framework to allocate the PEVs capacity to generate each power component considering to grid and vehicle constraints, technical concerns and market price. In the proposed framework, PEVs compete with active power-line conditioners (APLCs) to generate distorted power and with generators to produce active and reactive power. An objective function is defined which includes distribution system operator (DSO) payment for each market participant. This function is minimised based on a hybrid optimisation algorithm (HOA) combining artificial bee colony (ABC) and differential evolution (DE) algorithms subject to grid and vehicles constraints. In the presented algorithm, a novel self-adaptive modification phase is proposed to improve overall ability of the algorithm for optimisation applications. The effectiveness and efficiency of the method is demonstrated on a low-voltage network with 134 customers as a case study.

Dynamic Performance Improvement of a Grid-Tied PV System Using a Feed-Forward Control Loop Acting on the NPC Inverter Currents

This paper presents a three-phase grid-connected photovoltaic (PV) system, which is implemented using the neutral-point-clamped (NPC) inverter. A current feed-forward control loop (FFCL) is proposed to improve the PV system dynamic behavior, due to the PV array being constantly subjected to sudden solar irradiance change, which causes voltage oscillations in the dc bus and, hence, interferes in proper PV system operation. As the current FFCL acts to speed up the calculation of the inverter current references, the dynamic response of the currents injected into the grid is improved. As a consequence, the dynamic behavior of the dc-bus voltage is also enhanced, reducing both settling time and overshoot. Besides the injection of active power into the grid, the PV system is also controlled to perform active power-line conditioning, so that load harmonic currents are suppressed, as well as load reactive power is compensated. However, the NPC inverter must be properly designed to guarantee that its power rating will not be exceeded, since both fundamental and nonfundamental current components flow through the grid-tied inverter. Extensive experimental results based on a digital signal processor are presented in order to evaluate the effectiveness, as well as the static and dynamic performance of the PV system.

Optimal Placement and Sizing of Active Power Line Conditioners for Minimizing Power Quality Problems

<p>In this paper, a problem of allocation and sizing of multiple active power-line conditioners (aplcs) in power systems is handled with novel formulation. The utilized objective function comprises two main factors such as reduction of total harmonic distortion and the total cost of active power-line conditioners (aplcs). The formulated problem is solved by optimization technique SHUFFLE FROG LEAP ALGORITHM(SHFLA) using MATLAB. To evaluate the competence of the proposed formulation, the IEEE 18-bus distorted distribution test system is employed and investigated with various number of aplcs placement. These cases are based on the discrete and limited size for aplcs, requiring the optimization method to solve the constrained and discrete nonlinear problems. The comparison of results in this paper showed that the proposed SHFLA is the most effective result among others in determining optimum location and size of APLC in distribution systems.</p>

Simulation of an uninterruptible power supply based on active power line conditioner in the Simulink environment

The simulation of an uninterruptible power supply based on filter-compensating transducer parallel type carried out. The diagrams characterizing the operation of the system in reactive power compensation and a guaranteed power supply modes were built. The main parameter of the quality of consumed electricity is estimated.

Feed‐forward DC‐bus control loop applied to a single‐phase grid‐connected PV system operating with PSO‐based MPPT technique and active power‐line conditioning

This study deals with a double-stage single-phase grid-connected photovoltaic (PV) system operating with an additional feed-forward control loop (FFCL). Owing to the PV array being constantly subjected to abrupt solar irradiance change, the DC-bus voltage varies and can interfere in adequate PV system operation. Therefore, an FFCL is proposed to improve the DC-bus voltage dynamic response, and reduce the settling time and overshoot. The FFCL acts on the generation of the inverter current reference, such that the dynamic behaviour of the current injected into the grid is also improved. Furthermore, the PV system performance is affected by problems associated with mismatching phenomena such as partial shading. This problem can be overcome using the maximum power point tracking (MPPT) technique based on particle swarm optimisation (PSO). The PSO-based MPPT is compared with the conventional perturb-and-observe MPPT technique, in order to highlight its effectiveness. In this study, the PV system also performs active power-line conditioning. Thereby, whereas the step-up DC–DC converter carries out the MPPT, the proper inverter current reference is computed to inject active power into the grid, as well as perform power-line conditioning. The performance and effectiveness of the PV system are evaluated through extensive experimental tests.