Passive Filter Research Articles

Modeling non-linear loads for low-voltage electric grids

The authors performed the computer modeling of a power distribution grid section comprising a significant non-linear and asymmetric household and office load. The modeling was performed using the SimInTech software. The developed model was used to study the impacts that non-linear single-phase consumers (e.g. computers, printers, TV sets, microwave ovens, etc) have on the distortion of current and voltage curves in the grid and the formation of current in the transformer neutral. The authors demonstrate the dependency between the higher harmonic values of the phase and transformer neutral currents and the total non-linear consumer power, their share in the overall power substation load, and the distribution of non-linear consumer load across the substation feeders. To reduce the level of harmonic current components, the authors suggest using narrow-band passive higher harmonic filters. A computer model was developed for the simultaneous operation of a single-phase non-linear load and a four-link filter compensating device that comprises the filters set for the frequencies of the third, fifth, seventh, and ninth harmonics. The analysis of the non-sinusoidal operating modes of the grids with -harmonic filters connected showed that there is practically no current in the neutral while the distortion factors of the phase currents and grid voltage curves are at the minimum.

Rancang Bangun Multilevel Inverter dengan Filter Pasif L-C-L dan Teknologi IoT Untuk Memantau Perubahan Kecepatan Motor Induksi Satu Fasa

Multilevel inverter is a type of inverter used to generate AC signals with adjustable frequency and better quality. L-C-L passive filter is used to eliminate harmonic distortion in the generated AC signals. Meanwhile, IoT technology is used to remotely monitor and control the speed of the motor through a mobile application. In this thesis, the design of a flying capacitor multilevel inverter is used as an induction motor speed controller with the resulting Total Harmonic Distortion (THD) can be reduced if you add a level to the inverter. Then, L-C-L passive filter is designed to eliminate harmonic distortion in the generated AC signals. Furthermore, the implementation of IoT technology is carried out using Blynk IoT platform. The test results show that the multilevel inverter with L-C-L passive filter successfully generates AC signals with better quality compare without L-C-L passife filter. In addition, IoT technology is successfully implemented and allows users to remotely monitor and control the speed of the motor through a mobile application. Thus, the use of multilevel inverter with L-C-L passive filter and IoT technology can effectively increase the efficiency and control of single-phase induction motor.
 Keywords: multilevel inverter, L-C-L passive filter, IoT, induction motor, total harmonic distortion.

Optimal siting and sizing of custom power system and smart parking lot in the active distribution network

AbstractNon‐linear loads, electrical vehicles (EVs) and power electronics are the sources of harmonic generation in the power system. Harmonics are the reason for the disturbance in the technical constraints and quality of the power system. These disadvantages are formed in the current and the voltage of the system branches and buses. To reduce these harmonics, active and passive power filters are used. Since active power filters (APFs) include electronic power switching devices, they are used to eliminate or reduce current or voltage harmonics. To properly reduce these harmonics and supply consumer demand, private investors (PIs) are considered to enhance the power quality, by investing in the APF units and the distribution network operator (DNO) coordinating and feeding the EVs, by equipping the network with smart parking lots. Total harmonic distortion, bus voltage profile, active power loss and energy not supplied (ENS) are considered problem attributes. Using techniques for order of preference by similarity to the ideal solution (TOPSIS), it is determined how the addition of photovoltaic (PV), energy storage system, and batteries affects the ranking of attributes from the perspectives of both DNO and PI. The best solutions are obtained in the first stage using a genetic algorithm (GA), and the attributes have been prioritized from a utility perspective in the second stage by TOPSIS. To verify the performance of GA and TOPSIS, all of the obtained results are compared with the other algorithms. As seen clearly, active, reactive power loss and ENS in scenarios with the participation PV are reduced. Furthermore, comparing the results of different algorithms confirms the efficiency of GA and TOPSIS.

A Practical Method for Optimized Reactive Power Sharing Among Passive Filters

This paper presents a practical method for reactive power sharing among harmonics filters. The proposed method minimizes the total harmonic distortion of the current. The current is measured at the incoming bus to which harmonics filters are connected. The total harmonics distortion and individual harmonics of the voltage at the bus to which the harmonic filters are connected and the individual harmonics of the current measured at the mentioned measurement point are used as constraints of optimization. The Optimization Toolbox of MATLAB software is used in this paper. The simulation results show the efficiency and robustness of the proposed method.

Improved Structure for Three-Phase Four-Wires Hybrid Active Power Filters

This paper presents a novel three-phase four-wire low power rating flexible hybrid active filter with a power factor, harmonic and neutral currents capability for distribution systems. The passive filter is tuned to compensate the two largest harmonics components and the power factor of the load. A selective algorithm is employed in order to enable the active filter to compensate only the desirable harmonic components. Simulation results are presented in order to verify the performance of the proposed hybrid filter.

Control strategy to improve the power factor with a hybrid filter

Nowadays an electrical system must provide adequate electrical power quality so that it meets the international standards. To do this, this paper develops a control strategy for an active compensator based on a hybrid filter topology. This topology is formed by an active power filter of series connection and a passive filter of parallel connection. The proposed strategy is based on minimizing the rms value of the voltage at the point of common coupling so that the source transfers the power demanded by the load. Thus, the determination of the reference signal is posed as a constrained optimization problem. The strategy was proposed for four-wire systems and it allowed the compensation of current harmonics, reactive power and neutral current. Finally, a simulation platform in Matlab-Simulink was developed. This allowed the verification of the new strategy for different types of loads.

Analysis of the Energy Quality in a Building Acclimated Through a System of Evaporative Cooling Operated by Frequency Converters.

The present article has as the aim to analyze the level of harmonic distortion of voltage in the bus in an electric system in the presence of evaporative refrigerators used for the cooling of environments operated by converters of frequency in which measurement campaigns were carried out in field. Considering that the frequency converters with the filters absence make the system presents nonlinear characteristics whose analyses are of great matter in what concerns about the quality of the electric energy and the fulfillment of the law and the existing rule, established by the national and international regulating agencies. In this context, through computational simulations, there was observed the efficiency of the passive filters tuned with objective to reduce the levels of harmonic distortions of voltage in the bus in study and to adapt these levels to the standards of reference contained in the existing resolutions. 1

Centralized normalization of harmonic voltages by the third-order passive filter

The values of harmonic voltages at network nodes should meet the standard limits. Harmonic voltages can be decreased to admissible values on a centralized basis. The paper addresses the problem of centralized decrease of harmonic voltages in the high voltage networks with distributed nonlinear loads using third-order passive filters. Mathematical expressions to determine parameters of the third-order passive filter are given. The parameters of the selected filters for 220 kV network supplying traction substations with power and also the estimates of the efficiency of work of these filters for different network configurations are presented as an example. The efficiency of the C-type and third-order filters are compared.

Design of passive filter based on magnetic integrated technology for single‐phase grid‐connected inverter

AbstractIn response to the need for smaller and lighter power supply equipment, there has been a push towards higher power density in current power electronic converters. This development aligns well with the requirements of photovoltaic grid‐connected inverters. Among various passive filters utilized in these inverters, the LCL filter stands out as a popular choice. Nevertheless, it should be noted that traditional LCL filters have limited core utilization and exhibit significant redundancy. In view of the above problems, this paper proposes a magnetic integrated passive filter based on ripple transfer technology and carries out volume optimization design. Compared to the conventional LCL filter, the magnetic integrated passive filter offers a reduction in size and weight while preserving its capability to ripples attenuate. Finally, a laboratory prototype with a rated power of 2 kW is built to verify the effectiveness of the proposed magnetic integrated passive filter.

Harmonic Resonance Study for Wind Power Plant

Harmonic resonance is one of an important aspect being considered in a large network such as a wind power plant (WPP). This paper analyses several factors that affect resonance characteristic in a WPP and possible mitigation measures. The first part of the paper provides an analysis of resonances in WPP. Two methods of identifying resonances are performed which are a common impedance scan method and a harmonic resonance modal method for different operating conditions. Several factors that affect resonances including the usage of passive filters as harmonic mitigation in the network are analyzed. A case study of a 400 MW offshore wind power plant is analyzed for the harmonic resonance including with the integration of a passive filter.

Simulation and optimization of control parameters in energy hybrid filter

Two energy hybrid filter systems were considered which reduce level of higher mains current harmonics. An advantage of such system is low demanded active filter power because in complements only passive filter operation. The first considered system has inverter switched on in series with shunt passive filter. Through optimization of control parameters it is able to eliminate specific higher mains currents harmonics left by passive filter in a point by point way. The other tested system includes two inverters which are switched on to the system in series and shunt way. Their operation is to reduce higher mains current harmonics induced by higher load currents harmonics in a continuous way. The simulations carried out proved correct operation of the system.

An optimization approach to calculation of passive filter parameters based on particle swarm optimization

The paper presents an optimization approach to calculation of parameters of passive filters of different types for centralized reduction of harmonic voltages in the high-voltage network with distributed nonlinear loads. An optimization problem in which the minimum active power losses in the filter are used as an objective function has been formulated. Two forms of constraints for the objective function are suggested: constraints common to all types of filters and individual constraints to consider specific features of each type of filter. A two-stage algorithm based on the particle swarm optimization has been developed to solve the optimization problem. The application of the suggested algorithm to calculation of the thirdorder passive filter parameters is exemplified by a real 220 kV network.

Different LC power filter topologies - effectiveness of reducing voltage distortion

This Paper aims to present a comparative study of different passive filter configurations. Five topologies of passive RLC filters for the purpose of the mitigation of harmonics voltage distortion are considered. Basis for evaluating the effectiveness of different filter topologies are simulation and laboratory studies.

New control strategy to improve power quality using a hybrid power filter

A new control algorithm for a hybrid power filter constituted by a series active filter and a passive filter connected in parallel with the load is proposed. The new control strategy is based on the dual formulation of the vectorial theory of electric power, so that the signal injected by the active filter is able to compensate the reactive power and the harmonics of the load current. To verify the developed theoretical analysis, the control strategy was verified by means of an experimental prototype. The results to verify the effectiveness of the proposed control algorithm are presented.

Conservative Power Theory (CPT): A New Approach to the Tuned Passive Filter Design

The study of the effect of the harmonic distortions and the power factor in a system with presence of nonlinear loads becomes crucial to the quality of electrical energy. Based on this problem, this article uses the Conservative Power Theory to evaluate parameters associated to product quality, aiming to obtain subsidies for the design of tuned passive filters focused on the reduction of harmonic distortion indexes associated with voltage and current, in addition to contribute to the reactive compensation of the electrical system under research.

On-chip passive pump-rejection long-pass filters for integrated SiC-based nonlinear and quantum photonic chips

We present an on-chip passive pump-rejection filter on an integrated silicon carbide (SiC)-on-insulator photonic platform. Our filters exploit the optical absorption from an amorphous silicon (α-Si) thin-film layer deposited on the top surface and on the sidewalls of the SiC waveguide to reject light with a wavelength below 1.0 µm. The filter has a simple design and can be readily fabricated using a standard semiconductor wafer fabrication process and can be integrated as a pump-rejection filter component for SiC-based nonlinear and quantum photonic chips. We experimentally demonstrate a pump-rejection efficiency exceeding 230 dB/mm for 780 nm wavelengths, while we extract an insertion loss of ∼1 dB for the O-, C-, and L-bands.

Compensation of Voltage Unbalance and Current Harmonics with a Series Active Power Filter.

A combined system of shunt passive and series active filter for a four-wire three-phase system has been designed and simulated with Matlab/Simulink. The system combined mitigates the source current harmonics and compensates also unbalance voltages reducing the problems of using only a shunt passive filter. Therefore, a new control method based in the power vectorial theory has been proposed. The compensation principle is presented in detail. To verify the effectiveness of the proposed control, simulation results are presented and discussed.

Mixed H∞‐based finite‐time passive filtering for a class of uncertain nonlinear singular systems

AbstractThis article discusses the finite‐time mixed and passive filtering design problem for uncertain nonlinear singular systems. The parameter uncertainties are constrained by well‐defined upper bounds on their magnitudes. The objective is to design a full‐order filter to ensure that the augmented singular system to be finite‐time boundedness(FTB) with and passivity performance. Firstly, a sufficient condition for achieving singular finite‐time boundedness with mixed and passivity performance for uncertain nonlinear singular system is derived by introducing a free matrix. Secondly, a novel criterion is established for analyzing finite‐time and passivity problem of filtering error singular system based on augmented matrix technique. Thirdly, the filtering design conditions are presented and the relevant parameters of the desired filter are determined using linear matrix inequality decoupling principle. Finally, a practical circuit system and a numerical example are provided to demonstrate the feasibility of the proposed scheme.

A 125–600-MHz IF 75-dB DR Partially Time-Interleaved Bandpass DSM Based on Passive N-Path Filters

A 125–600-MHz IF 75-dB DR Partially Time-Interleaved Bandpass DSM Based on Passive N-Path Filters

Generalized Dissipativity-Based Receding Horizon FIR Filtering with Deadbeat Property

This paper proposes a new approach to designing the receding horizon finite impulse response (FIR) filter based on the generalized dissipativity concept. A new sufficient condition is established in the form of the linear matrix inequality (LMI) and linear matrix equality (LME) for generalized dissipative FIR filtering with deadbeat property. In contrast to the existing works on FIR filtering, this paper presents the <formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex>$H_{\infty}$</tex> </formula> FIR filter, the <formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex>$l_{2}-l_{\infty}$</tex> </formula> FIR filter, the passive FIR filter, and the <formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex>$(\cal{Q}, \cal{S}, \cal{R})-\alpha$</tex> </formula> -dissipative FIR filter in a unified framework. A design condition for the generalized dissipative FIR filter (GDFF) without LME is also discussed. By means of a numerical example, it is shown that the developed approach provides an FIR filter with more robustness against unpredictable short-time model changes than the existing ones.