Shunt Passive Filter Research Articles

Optimal C-type filter for harmonics mitigation and resonance damping in industrial distribution systems

Single-tuned passive filters offer reasonable mitigation for harmonic distortion at a specific harmonic frequency with a high filtering percentage, but resonance hazards exist. Traditional damped filters offer high-pass filtering for the high-frequency range, but suffer from extra ohmic losses. C-type filters may operate in a manner similar to the tuned filters with low damping losses and marginal resonance damping capabilities. In addition, they can be designed as damped filters with increased resonance damping capability. In this paper, a methodology that facilitates sizing for the C-type damped filter parameters for harmonics mitigation and resonance damping in balanced distribution system networks is presented and discussed using the impedance-frequency index. This index evaluates the resonance damping capability provided by the damped filters analytically rather than the conventional graphical method of impedance-frequency scanning. It shows how to size shunt passive filters, while making a full use of their damping capabilities. It can disclose the parallel resonance frequencies of the equivalent system-filter impedance. A comparative study of the new approach and a conventional filter design approach, which aims to minimize total harmonic current distortion, is presented. Numerous simulation results are provided to clarify the proposed methodology, advantages, and disadvantages.

Experimental Verification of Quasi Z-Source Inverter Based Hybrid Series Active Power Filter for Interconnection of PV into the Utility Grid

This paper proposes a Photovoltaic/Battery interfaced Quasi Z-source inverter based three-phase four-wire Hybrid Series Active Power Filter (HSAPF)to compensate the voltage and current related power quality problem in small distributed power system. The HSAPF consists of shunt passive filter and series active filterconsuming a battery. The shunt active filter mitigates the current harmonics generated by a nonlinear load. The series active filter mitigates the voltage sag/swell and load voltage harmonics, which consumes the power from Photovoltaic (PV) array with quasi Zsource inverter (qZSI). A new controller of qZSI based HSAPF uses two control schemes to boost the PV/Battery output voltage and achieve maximum power point tracking PV array. The simulation and experimental results are presented to validate the performance of proposed qZSI based HSAPF.

USING HYBRID POWER FILTER TO MITIGATE CURRENTS AND VOLTAGES HARMONICS IN THREE PHASE SYSTEM

This paper describes different power quality problems in distribution systems and their solutions with power electronics based equipment. A hybrid power filter in combined system of shunt passive and series active power filter has been designed and simulate with Matlab/Simulink. This filter is a three level PWM voltage source inverter and we use a fuzzy logic controller algorithm to control the harmonic voltages. The viability of the proposed algorithm is validated in this work. This hybrid power filter is able to compensate the reactive power (showed that source voltage is sinusoidal and in phase with source current), and harmonics (voltage & current) for three phase of the non linear load current proposed with RL and RC load. The proposed solution has achieved an improvement of power quality in distribution system specifically the reduction of currents and voltages harmonics, we see that through the values of THDI and THDV that are still below the IEC (61000) standard after filtering.

English

This Paper describes Power Quality Problems in Power system and there solutions with Power electronics based equipements.Several international standard issues to control power quality are briefly described and some important methods to analyses Electrical Circuit with non-sinusoidal waveforms are introduced and evaluated. Passive filters, Shunt, hybrid and series active power filters are described showing their compensation characteristics and principles of operation .Different power circuit’s topologies and control scheme for each type of power filter are analyzed. The compensation characteristics of each topology with respective control scheme are proved by simulation and experimentally. The filter can compensate for harmonic current, power factor and load unbalance. A power filters which has been used there monitors the load current constantly and continuously adapt to the changes in load harmonics.

Three Phase Auto-tuned Shunt Hybrid Filter for Harmonic and Reactive Power Compensation

Abstract Hybrid filters are highly recommended for harmonic and reactive compensation in existing installations. Since current harmonic compensation can limit voltage harmonics also to a great extent, shunt hybrid filters are preferred. The traditional shunt hybrid filter consists of shunt passive and shunt active filter. Here, shunt passive filter provides fixed compensation at all load conditions. Therefore, probably at low load conditions, shunt passive filter acts as major consumer. This embarrassing situation can be avoided by replacing traditional shunt passive filter with the shunt auto-tuned passive filter. The shunt auto-tuned passive filter uses an ANN based controller to select passive filter components to provide adequate harmonic and reactive compensation under all load conditions. Remaining harmonic and reactive power compensation are provided by ANN based active filter. The performance of the proposed hybrid filter was tested by simulation and laboratory experiments under various source/load conditions and the results show that the proposed shunt hybrid filter is adaptive to varying source/load conditions.

THREE-PHASE FOUR-WIRE PV-BASED SERIES HYBRID ACTIVE POWER FILTER FOR POWER QUALITY IMPROVEMENT

This paper proposes a photovoltaic (PV)-based three-phase four-wire (3P4W) series hybrid active power filter (SHAPF) it comprises of a series active power filter (SAPF) and an LC shunt passive filter. The proposed system eliminates both the current and voltage harmonics and compensates reactive power, neutral current and voltage interruption. A SAPF demands a source of energy for compensating the voltage sag/swell. This system introduces a new topology for SHAPF utilizes the PV with DC–DC boost converter as a source of DC power for SAPF. The compensation current reference evaluation is based on the twin formulation of the vectorial theory of electrical power theorem with fuzzy logic controller (FLC). The PV array/battery managed DC–DC boost converter is employed to step up the voltage to meet the DC bus voltage requirement of the three-leg voltage source inverter (VSI). The foremost benefit of the proposed system is that, it will provide uninterrupted compensation for the whole day. This system utilizes the renewable energy accordingly saves the energy and shares the load during the solar irradiation available. The simulation and experimental studies are carried out to validate the effectiveness of the proposed PV-SHAPF.

Experimental Verification of Photovoltaic-based Three-phase Four-wire Series Hybrid Active Power Filter

—This article proposes a photovoltaic and battery interfaced series hybrid active power filter, which is comprised of a series active power filter and an inductor-capacitor (LC) shunt passive filter. The main benefits of the proposed system provide the compensation against the voltage harmonics, current harmonics, and voltage interruption for the whole day. A series active power filter demands a source of energy for compensating the voltage sag/swell. The proposed topology utilizes the green energy source with an energy storage unit to meet the DC-link voltage requirement of the series active power filter. The control strategy is based on the dual formulation of the compensation system principles with adaptive fuzzy logic controller. The simulation and experimental studies are carried out to validate the effectiveness of the proposed photovoltaic interfaced three-phase four-wire series hybrid active power filter.

English

In this work a new control strategy for simulation of three phase hybrid power filter for power quality improvement is adapted. This filter consists of shunt passive LC power filter and series active filter, with nonlinear balanced and unbalanced loads and also with variation in the source impedance. A new control method based on dual formulation of instantaneous reactive power vectorial theory is applied by considering a balanced and resistive load as reference load, so that the voltage waveform injected by the active filter is able to attain the objective of achieving reactive power compensation. This also helps in eliminating load current harmonics and also in balancing asymmetrical loads i.e., for achieving ideal behaviour for the set hybrid filter load, Total Harmonic Distortion (THD) is reduced and power factor is improved. This method improves passive filter compensation characteristics without depending on system impedance, avoids the danger of passive filter behaves as harmonic drain of close loads and avoiding series and / or parallel resonance problems. And compensation is also possible with variable loads without detuning the passive filter. And is applied for creating LG/LL faults at the source side. The results show that the active filter improves the compensation characteristics of the passive filter and reactive power is compensated.

Design and implementation of PV-based three-phase four-wire series hybrid active power filter for power quality improvement

This paper proposes a Photovoltaic (PV)-based three-phase four-wire Series Hybrid Active Power Filter (SHAPF), it comprises of a Series Active Power Filter (SAPF) and an LC shunt passive filter. The proposed system eliminates both the current and voltage harmonics and compensates reactive power, neutral current and voltage interruption. A SAPF demands a source of energy for compensating the voltage sag/swell. This system found a new topology for SHAPF which utilizes the PV with DC–DC boost converter as a source of DC power for the series active filter. The compensation current reference evaluation is based on the twin formulation of the vectorial theory of electrical power theorem with Fuzzy Logic Controller (FLC). The PV array/battery managed DC–DC boost converter is employed to step up the voltage to meet the DC bus voltage requirement of the three-leg Voltage Source Inverter (VSI). The foremost benefit of the proposed system is that, it will provide uninterrupted compensation for the whole day. This system utilizes the renewable energy; accordingly saves the energy and provides the uninterruptable power supply to critical/sensitive load, through the PV array/battery bank during both day time and night time. An experimental model was established and results were obtained, which indicated the capability of the proposed control scheme.

A Combination of Shunt Hybrid Power Filter and Thyristor-Controlled Reactor for Power Quality

This paper proposes a combined system of a thyristor-controlled reactor (TCR) and a shunt hybrid power filter (SHPF) for harmonic and reactive power compensation. The SHPF is the combination of a small-rating active power filter (APF) and a fifth-harmonic-tuned LC passive filter. The tuned passive filter and the TCR form a shunt passive filter (SPF) to compensate reactive power. The small-rating APF is used to improve the filtering characteristics of SPF and to suppress the possibility of resonance between the SPF and line inductances. A proportional-integral controller was used, and a triggering alpha was extracted using a lookup table to control the TCR. A nonlinear control of APF was developed for current tracking and voltage regulation. The latter is based on a decoupled control strategy, which considers that the controlled system may be divided into an inner fast loop and an outer slow one. Thus, an exact linearization control was applied to the inner loop, and a nonlinear feedback control law was used for the outer voltage loop. Integral compensators were added in both current and voltage loops in order to eliminate the steady-state errors due to system parameter uncertainty. The simulation and experimental results are found to be quite satisfactory to mitigate harmonic distortions and reactive power compensation.

A New Approach for Harmonic Distortion Minimization in Power Systems Supplying Nonlinear Loads

In view of many problems associated with harmonics pollution within industrial firms, the development of new passive and/or hybrid filtering techniques of higher quality, higher efficiency, and lower cost is a necessity for the forthcoming power quality age. This article suggests a hybrid passive filter, which consists of a certain combination of a shunt passive filter (SPF) with a series passive portion as a substitute to overcome the shortcomings of conventional shunt passive filtering techniques. Constrained optimization is used to find the optimal sizing of parameters of the hybrid passive filter in order to reduce both harmonic voltages and harmonic currents in the power system to an acceptable level, as well as to improve the load power factor. The optimal design of the hybrid passive filter and its feasibility are compared with those of the C-type passive filter and the conventional SPF by means of four study cases taken from existing publications. Several simulation results are shown in order to highlight the viability of the proposed filter.

Harmonic convergence for balanced and unbalanced non-linear load using hybrid filter

A control strategy is suggested for converging harmonics with hybrid filter. The hybrid power filter is constituted by a series active filter and shunt passive filter. The control algorithm works on dual formulation of electric power vectorial theory. Without depending on the system impedance, the active filter improves the compensation characteristic of the shunt passive filter and eliminates the series/shunt resonance problem, the voltage waveform injected by the active series filter is able to compensate for reactive power, eliminates harmonics in load current and balances asymmetrical load.

Optimal Sizing ofC-Type Passive Filters under Non-Sinusoidal Conditions

In the literature, much attention has been focused on power system harmonics. One of its important effects is degradation of the load power factor. In this article, a C-type filter is used for reducing harmonic distortion, improving system performance, and compensating reactive power in order to improve the load power factor while taking into account economic considerations. Optimal sizing of the C-type filter parameters based on maximization of the load power factor as an objective function is determined. The total installation cost of the C-type filter and that of the conventional shunt (single-tuned) passive filter are comparatively evaluated. Background voltage and load current harmonics are taken into account. Recommendations defined in IEEE standards 519-1992 and 18-2002 are taken as the main constraints in this study. The presented design is tested using four numerical cases taken from previous publications, and the proposed filter results are compared with those of other published techniques. The results validate that the performance of the C-type passive filter as a low-pass filter is acceptable, especially in the case of lower short-circuit capacity systems. The C-type filter may achieve the same power factor with a lower total installation cost than a single-tuned passive filter.

A Transformerless Series Reactive/Harmonic Compensator for Line-Commutated HVDC for Grid Integration of Offshore Wind Power

This paper introduces, explains, and investigates the application of a transformerless series-connected reactive/harmonic compensator. The proposed compensator is applied to compensate the high reactive-power/harmonic demand of a 12-pulse line-commutated HVDC rectifier terminal. Simulation results reveal that the proposed strategy compensates the reactive power and harmonics of the HVDC converter satisfactorily. All of this is achieved using significantly smaller capacitance at the compensator dc link than the capacitance required in the state-of-the-art shunt compensators employing passive components. The compensator thus would eliminate the need of fundamental-frequency reactive power supply and minimize (or eliminate altogether) the requirement of passive shunt harmonic compensation. This would result into smaller shunt passive filters, smaller or no shunt capacitor banks, and smaller converter transformers, leading to a more compact HVDC terminal, the current size of which is considered to be the main hurdle in its application for integration of large-scale offshore wind energy. Experimental results from a small-scale setup validate the effectiveness observed in the simulations.

Different Design Approaches of Shunt Passive Harmonic Filters Based on IEEE Std. 519-1992 and IEEE Std. 18-2002

Most of the equipment found in the modern electrical installations can be considered as harmonic sources. Harmonic pollution causes serious problems to all electrical users. Many solutions are used to limit the problems related to harmonics and other power quality disturbances. The most used approach is to use shunt passive filters due to their simplicity, economical cost and their various frequency response characteristics. This article presents an application of FORTRAN Feasible Sequential Quadratic Programming package (FFSQP), in which it is implemented to deal with the constrained optimization of conflicting goals which allow the appropriate calculation of optimal shunt passive filter parameters. The article includes different optimization criteria depending on the designer concerns. Furtherer more, a mathematical model of a single tuned shunt filter on economical basis is demonstrated to select the size of its parameters with minimum total cost, providing improvement of the load power factor and complying with the IEEE standard 18-2002 limits. This article presents some promising patents for assessment of the optimal design for harmonic passive filter of multi-constraint and multi-objective functions.

ANN based Hybrid Active Power Filter for Harmonics Elimination with Distorted Mains

The present paper describes dynamic neural network controlled Hybrid Active Power Filter (HAPF) designed for harmonic compensation under variable source/load conditions. A neural network based controller is employed to extract fundamental component of current from non-sinusoidal and unbalanced source currents of the considered supply system. Hybrid filter utilizing the merits of both shunt passive filter and shunt active filter for better compensation performance is applied in this work. Simulation and analysis of three phase hybrid active power filter under balanced and unbalanced load conditions, unbalanced & distorted source conditions have been incorporated using MATLAB/ SIMULINK. The detailed simulation level results have been presented to validate the proposed methodology. Keywords: Hybrid active power filter, THD, Artificial Neural Network Controller, PI controller. DOI: http://dx.doi.org/10.11591/ijpeds.v2i3.276

Field-Data-Based Modeling of Medium-Frequency Induction Melting Furnaces for Power Quality Studies

In this paper, the coreless, medium frequency induction melting furnace (IMF) system, has been represented by alternative field-data-based models, developed specifically for power quality studies. The IMF operation has been represented by a variable series RL circuit to model the fundamental components of electrical quantities, and a shunt-connected current source, to model the generated harmonics and interharmonics over a typical melting cycle. Both the sinusoidal coding method applied to the major harmonics and interharmonics in the supply line currents obtained from field measurements and also raw data, have been used in the developed models. It has been shown that the sinusoidal coding method can be used to satisfactorily represent the operation of the IMF system as seen from the supply terminals, with a minimum data storage requirement, and can be used to construct efficient IMF databases for power quality studies. The power quality problems of the IMF system, in particular the problematic time-varying interharmonic voltage distortion, and the interaction of those time-varying interharmonic currents with the passive shunt filter installations connected to the same bus have been investigated in detail, using the developed models.

New Topologies for Static Reactive Power Compensator Based on PWM AC Choppers

Nowadays, static reactive power control is widely used in electrical power networks. The former solution based on Thyristor Controlled Reactors is progressively replaced by PWM Voltage Source Inverters. The first solution is quite simple but requires bulky shunt passive filters whereas the second solution shows higher semiconductor losses and requires a significant cooling system. In this paper, the authors present new topologies which show a good compromise in comparison to the classical solutions. Single phase AC Choppers are used to achieve controlled impedances (capacitive or inductive) at the fundamental frequency and thus adjust the reactive power level. This concept is applied for medium or high power applications and multi-converter structures based on step down or step up AC choppers are proposed. An example of design concerning reactive power compensation in a 25 kV/50 Hz AC traction line is presented. Finally, experimental results obtained for a 1.2 MVAR prototype demonstrate the feasibility of these novel topologies.

A Control Strategy for Hybrid Power Filter to Compensate Four-Wires Three-Phase Systems

A control algorithm is proposed for a three-phase hybrid power filter constituted by a series active filter and a shunt passive filter. The control strategy is based on the dual formulation of the compensation system principles. It is applied by considering a balanced and resistive load as ideal load, so that the voltage waveform injected by the active filter is able to compensate the reactive power, to eliminate harmonics of the load current and to balance asymmetrical loads. This strategy improves the passive filter compensation characteristics without depending on the system impedance, and avoiding the series/shunt resonance problems, since the set load-filter would present resistive behavior. An experimental prototype was developed and experimental results are presented.

A Hybrid Passive Filter Configuration for VAR Control and Harmonic Compensation

This paper proposes a novel topology for a three-phase hybrid passive filter (HPF) to compensate for reactive power and harmonics. The HPF consists of a series passive filter and a thyristor-controlled-reactor-based variable-impedance shunt passive filter (SPF). A mutual-inductance design concept is used to reduce the series passive filter inductance rating. The special features of the proposed HPF system are as follows: 1) insensitivity to source-impedance variations; 2) no series or parallel resonance problems; 3) fast dynamic response; and 4) significant size reduction in an SPF capacitor. The performance of the proposed HPF system is validated by simulation, as well as by experimentation, under different load conditions. Experimental and simulation results show that the proposed system can effectively compensate all voltage and current harmonics and reactive power for large nonlinear loads.