Order Harmonic Suppression Research Articles

A Single DC-Link Multilevel 42-Sided Polygonal Voltage Space Vector Generation With Lower Order Harmonic Suppression Using Switched-Capacitor Filter

In this work, a multilevel 42-sided polygonal space vector structure for suppression of lower order harmonics for open-end induction motor (OEIM) drive applications is proposed. The proposed power circuit topology consists of two inverters feeding an OEIM from either side. The main inverter fed with a single dc-link providing active power for motoring operation is switched at low switching frequency. The secondary inverter fed with a capacitive supply is switched at high frequency to suppress lower order harmonics upto 39th order, up to the base speed of operation allowing maximum utilization of the dc-link. The advantages of lower order harmonic suppression in motor phase voltage, for polygonal space vector structures, are combined with multilevel inverter topology. This offers various advantages like multilevel operation with low inverter switching for the main power delivery inverter and harmonic suppression throughout the modulation range. The low switching frequency primary inverter generates harmonics of the order <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$6*k \pm 1$</tex-math></inline-formula> , where <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$k = 1, 2, 3,{\ldots }$</tex-math></inline-formula> . The harmonics are suppressed by the capacitor-fed secondary inverter, which supplies only reactive power for suppression of lower order harmonics in motor phase voltage. Use of a single dc-link facilitates four-quadrant operation of the inverter. The proposed scheme is validated for steady-state and dynamic performance by experimental results.

Development and validation of enhanced fuzzy logic controller and boost converter topologies for a single phase grid system

Introduction. Solar photovoltaic system is one of the most essential and demanding renewable energy source in the current days, due to the benefits of high efficiency, reduced cost, no pollution, and environment friendly characteristics. Here, the maximum power point tracking controller has been implemented for obtaining an extreme power from the photovoltaic array. For this purpose, there are different controller and converter strategies have been deployed in the conventional works. It includes perturb and observation, incremental conductance, fuzzy logic systems, and hill climbing, and these techniques intend to extract the high amount of power from the solar systems under different climatic conditions. Still, it limits with the issues like increased design complexity, high cost consumption, high harmonics, and increased time consumption. The goal of this work is to deploy an improved controlling and converter topologies to regulate the output voltage and power fed to the single phase grid systems. The novelty of the work aims to develop an enhanced fuzzy logic controller based maximum power point tracking mechanism with the boost DC-DC converter topology for a single phase grid tied photovoltaic systems. Practical value. Also, the higher order harmonics suppression and unbalanced current elimination are handled by the use of LCL filtering technique, which efficiently reduces the harmonics in the output of inverter voltage and current. Moreover, it helps to obtain the reduced total harmonics distortion value with improved accuracy and efficiency. Results. There are different performance indicators have been evaluated for validating the proposed enhanced fuzzy logic controller–maximum power point tracking controlling technique. Moreover, the obtained results are compared with some of the conventional controlling algorithms for proving the betterment of the proposed work.

Coupled-line co-directional coupler with inherent harmonic suppression and its wideband implementation

In the study, a novel implementation of the coupled-line co-directional (CL-COD) coupler is proposed for the first time, and the wideband realizations are also demonstrated. The CL-COD coupler, which is composed of inductor loaded parallel coupled line and a pair of open-circuited stubs, has the advantages of smaller size and inherent harmonics suppression compared with the traditional λ/4 branch line coupler. Design equations of the single-section CL-COD coupler are derived by the even-odd mode decomposition analysis and a prototype is designed for validation. The experimental results indicate that compared with the traditional single-section λ/4 branch line coupler, the designed single-section CL-COD coupler shows a size reduction of 64.1%, a bandwidth enhancement of 13%, and a second harmonic suppression of more than 20 dB. By cascading multi-sections of the CL-COD couplers, wideband CL-COD coupler with harmonics suppression is also realized. A computer-aided program is applied for solving the circuit parameters of the multi-section cascaded CL-COD coupler. Besides, the two- and three-section cascaded 3-dB CL-COD couplers are designed for guidance. Finally, a 3-dB three-section cascaded CL-COD coupler is fabricated and measured. Compared with the traditional three-section cascaded λ/4 branch line coupler, the prototype shows a size reduction of 61.9% with an additional second order harmonic suppression.

Broadband circular polarized patch antenna with harmonic suppression

Background/Objectives: To develop Circular Polarized (CP) patch antenna with improved bandwidth and harmonic suppression for RF energy harvesting system. Methods/Statistical analysis: A l /4 resonator is introduced and coupled in proximity to the radiating patch for bandwidth enhancement and high order harmonic suppression. Compared with other dual-resonance patch antennas, the proposed antenna has attractive low-profile property and simple structure. The CP can be achieved by putting arc shape slits at edge of circular patch. The structure, working principle and results we are described. Findings/Applications: The operating bandwidth is from 1.68 GHz to 2.95 GHz (52.91%) with a reflection coefficient less than -10 dB with Axial Ratio bandwidth of 550MHz (2.21 GHz -2.76 GHz) while harmonic suppression over wide frequency range from 1 to 12 GHz is achieved. The experimental and simulated results is good matching except some slight variation. Novelty/Applications: New techniques for both bandwidth enhanced and harmonic suppression and up to 4th higher order harmonics has been suppressed. Proposed structure offers wideband CP Antenna with harmonic suppression. Keywords: RF energy harvesting; microstrip patch antenna; harmonic suppression; circular polarization

RETRACTED: An approach towards selective harmonic elimination switching pattern of cascade switched capacitor twenty nine-level inverter using artificial bee colony algorithm

Abstract This paper introduces harmonic removal in a Switched capacitor multilevel inverter utilizing artificial bee colony (ABC) method. The main focus is to neglect lower order harmonics by resolving nonlinear equation. In our paper, ABC algorithm is enforced to a twenty nine level inverter for resolving the equation. Selective Harmonics Elimination PWM is mainly used in lower order harmonics suppression. The MLI gets input from the SEPIC converter that comprises of Photo Voltaic Module as a source of generation. The PV panel output voltage is maintained constantly with a greater gain DC-DC SEPIC converter. Hence to obtain high power from the PV system, gray Wolf Optimization technique and fuzzy logic control is used. The high frequency modulation technique i.e. Multi Carrier modulation technique is too applied in the proposed new topology for reducing the higher order harmonics. The proposed ABC harmonics elimination technique is also compared with genetic algorithm based SHE method. MATLAB simulation platform is utilized to simulate the module. The experimental verification of the proposed work was done using DSPIC30F2010 controller.

Suppression of Lower Order Harmonics for the Full Modulation Range for a Two-Level Inverter-Fed IM Drive With a Switched-Capacitive Filter Technique Forming a 42-Sided Voltage Space Vector Structure

This article proposes an inverter topology for the first time for suppression of all lower order harmonics (5th, 7th, 11th, 13th, etc.) up to 39th harmonic. The lower order harmonic suppression is achieved by switching the 42-sided polygonal vectors, which eliminates harmonics in phase voltage without using a passive LC filtering technique. The power circuit topology uses a single dc-link supply for the primary inverter. The secondary inverter is fed with a capacitive supply. A novel topology is proposed for the dense six-level secondary inverter. The lower order harmonics in phase voltage are suppressed using the secondary inverter, which acts like a switched-capacitive filter. This article also proposes a novel capacitor voltage-balancing scheme for the first time, which achieves voltage balancing for secondary inverter capacitors. The voltages of secondary inverter capacitors are balanced using the power balance relationship between the primary inverter and the motor load. An experimental study of the topology and the capacitor-balancing scheme is presented for the validation of proposed scheme.

Dual-band aperture coupled antenna with harmonic suppression capability

The paper presents an aperture-coupled dual-band linearly-polarized antenna with harmonic suppression capability, operating at frequency 2.45 GHz and 5.00 GHz. In purpose of improving the directivity of antenna at the operating frequency of 2.45 GHz and 5.00 GHz, a modified inverted π-shaped slot-etched patch on the lower layer of the stacked antenna is introduced alongside the 50 Ω feed line. The harmonic suppression capability is achieved by the introduction of U-slot and asymmetrical left-right-handed stub at the transmission feed line, suppressing unwanted harmonic signals from 6.00 GHz up to 10.00 GHz. The final design of the antenna has produced very good reflection coefficient of -18.87 dB at 2.45 GHz and -19.57 dB at 5.00 GHz with third and higher order harmonic suppression up to -4 dB.

Low-Profile Independently- and Concurrently-Tunable Quad-Band Antenna for Single Chain Sub-6GHz 5G New Radio Applications

This paper presents a quad-band frequency agile antenna, with independent and concurrent frequency tunability in each band, for a tunable, concurrent, quad-band single chain radio receiver for 5G New Radio (NR). More specifically, the antenna comprises of four planar slots etched in a ground plane and fed through a single microstrip feedline, without any impedance matching network. The structure is optimized to maximize isolation between the individual slots and their respective resonant frequencies. Furthermore, a novel high order harmonic suppression method is demonstrated, which controls the current distribution via creating a fictitious short circuit in the slot antenna–enabling the antenna to achieve a much wider tuning range. Numerical simulations are verified using experimental implementation and measurements, with good agreement observed. The four slots resonate around the 830 MHz, 1.8 GHz, 2.4 GHz and 3.4 GHz frequency bands, which are independently tuned (using a varactor diode in each slot) to achieve tuning ranges of approximately 64%, 66%, 27% and 33%, respectively. More importantly, the contiguous four bands covers a total frequency tuning from 0.6 to 3.6 GHz i.e. a tuning range of approximately 143%. Finally, far-field measurements are performed and the antenna is evaluated in over-the-air testbed (quad-band radio receiver), which measures the Error Vector Magnitude performance for the individual channels. Good performance is observed, confirming acceptable isolation performance between the four bands. The data reported in this paper is available, from ORDA-The University of Sheffield Research Data Catalogue and Repository, at https://doi.org/10.15131/shef.data.11219000.v1 .

High Efficiency and Low EMI Wireless Power Transmitter Module with on-chip V/I Monitoring Circuits

A WPT (Wireless Power Transfer) transmitter for the magnetic resonance coupling method of A4WP (Alliance for Wireless Power) is implemented with on-chip V/I sensing circuits. Onchip integration leads us low power and small size PTU (Power Transmitting Unit) on a board. By V/I monitoring the symmetry of PA outputs can be maintained achieving high power efficiency and EMI suppression. The achieved power efficiency is 90% and 3SUPrd/SUP and 5SUPth/SUP order harmonic suppression are improved by 3.43 dB and 5.1 dB.

Higher order harmonics suppression in extreme ultraviolet and soft x-ray**Project supported by the National Key Research and Development Program of China (Grant No. 2017YFA0206004), the National Natural Science Foundation of China (Grant No. 11375160), and the National Science Instruments Major Project of China (Grant No. 2012YQ130125).

The extreme ultraviolet and soft x-ray sources are widely used in various domains. Suppressing higher order harmonics and improving spectral purity are significant. This paper describes a novel method of higher order harmonics suppression with single order diffraction gratings in extreme ultraviolet and soft x-ray. The principle of harmonic suppression with single order diffraction grating is described, and an extreme ultraviolet and soft x-ray non-harmonics grating monochromator is designed based on the single order diffraction grating. The performance is simulated by an optical design software. The emergent beams of a monochromator with different gratings are measured by a transmission grating spectrometer. The results show that the single order diffraction grating can suppress higher order harmonics effectively, and it is expected to be widely used in synchrotron radiation, diagnostics of laser induced plasma, and astrophysics.

Theoretical and experimental study of arbitrary microwave signal generation through LiNbO3 MZI

Microwave photonics system provides high bandwidth capabilities of fiber optic systems and also contains the ability to provide interconnect transmission properties, which are virtually independent of length. In this paper, we have studied the effect of higher order dispersion, harmonic suppression of forth order with different modulation values. We found that, higher order harmonic suppression and frequencies are varying with the electrical drive signal for different modulation depths. It is apparent from the calculated result that the harmonic suppression increases as the modulation depth increases. In all the case, it is observed that the harmonic suppression is varying, but the frequencies are same for different values of depth of modulation. The analysis performed by the other researchers describes that, harmonic suppression varies with frequency. But in our analysis, we found that harmonic suppression is independent of frequency. Thus, it can be beneficial; as electric signal is stable over the tuning band. In this paper, we derived the step by step expression for harmonic suppression for better understanding.

Impedance-Varying Broadband 90° Branch-Line Coupler With Arbitrary Coupling Levels and Higher Order Harmonic Suppression

We propose a new design methodology to broaden the bandwidth of a single-section 90° branch-line coupler (BLC) with arbitrary coupling level. The method used here to broaden the BLC bandwidth is to replace conventional uniform transmission lines that would never be feasible in many implementations with nonuniform lines governed by a truncated Fourier series. Based on how impedances are profiled, the fractional bandwidth of a single-section 90° 3-dB BLC is extended to 57%, and the realization of broadband BLCs with predefined coupling levels is also possible. Furthermore, higher order harmonics are suppressed by enforcing BLC $S$ -parameters to match the design requirements only at a given frequency range. A systematic design approach based on the even-odd mode analysis is first presented. Then, three examples of 3-, 6-, and 9-dB BLCs are demonstrated at a 3-GHz center frequency. The obtained theoretical response, supported by full-wave electromagnetic simulations and measurements, justifies the design concept.

Using Microstrip LPF in Gysel Power Divider for Extreme Size Reduction and Higher Order Harmonic Suppression

AbstractThis paper presents a new design of a compact Gysel power divider with harmonic suppression. It comprises six similar low-pass filters in lieu of six conventional transmission lines in the Gysel power divider. Not only does the proposed power divider extremely reduce the occupied area to 22.7% of the conventional Gysel power divider at 900 MHz, but also it features the higher order harmonic rejection. Simulation and measurement results show good insertion loss, return loss, isolation, and wide stopband bandwidth, while maintaining high-power handling capability over the Wilkinson power divider.

DESIGN OF A COMPACT WILKINSON POWER DIVIDER WITH HIGH ORDER HARMONICS SUPPRESSION

A new method for designing compact Wilkinson power dividers with three order harmonics suppression is presented. The quarter-wavelength transmission line in the traditional Wilkinson power divider is replaced by two pairs of parallel coupled lines with one end connected in series with an open stub. With this structure, the quarter-wavelength line will be shorter and three attenuation poles can be added in the stopband. As a result, this newly proposed structure carries the functions of impedance matching at operating frequency and three orders harmonics suppression. In this study, an example of power divider operating at 1 GHz is designed and fabricated. The measured results show good performance at the operating frequency. In addition, the second, third and fourth harmonics suppressions are 43 dB, 49 dB and 37 dB, respectively, which validates the feasibility of the proposed design.

A MODIFIED MICROSTRIP WILKINSON POWER DIVIDER WITH HIGH ORDER HARMONICS SUPPRESSION

In this paper, a modifled Wilkinson power divider structure with three order harmonics suppression is presented. The quarter-wavelength microstrip lines in the traditional Wilkinson power divider (WPD) are replaced by two transmission line segments with ends connected (TTLWEC). The TTLWEC performs the functions of impedance transformation and three order harmonics suppression. The design equations are deduced by odd- and even-mode theory. An example of power divider operating at 1GHz is designed and fabricated based on the printed circuit board technology. The measured results of 3.13dB insert loss (IL) and 35dB return loss (RL) are obtained at the operating frequency, and the flrst, second and third harmonic harmonics suppressions are i38dB, i44dB and i39dB, respectively, which agree well with the simulated results and validate the availability of the proposed structure.

WIDEBAND NEGATIVE PERMITTIVITY METAMATERIAL FOR SIZE REDUCTION OF STOPBAND FILTER IN ANTENNA APPLICATIONS

The design and simplifled analysis of a compact and wide band (16%) negative permittivity complementary split ring resonator metamaterial is introduced. The proposed metamaterial component was applied to reduce the size of the feeding line fllter of microstrip patch antenna for the sake of higher order harmonic suppression. The reduction has been done using only one element of complementary split ring resonator, while maintaining the antenna's performance. Simplifled theoretical study and design of the proposed circuits has been presented. Moreover, experimental results have been done for validation and conformation purpose. Results conflrm that almost 95% of the antenna noise harmonics power has been removed.

Miniaturized Microstrip Wilkinson Power Divider With Harmonic Suppression

A microstrip Wilkinson power divider with harmonic suppression and size reduction is presented in this letter. The proposed power divider not only effectively reduces its occupied area to 36.5% of the conventional design at 2.65 GHz but also has higher order harmonics suppression. From the measured results, a 29 dB suppression for the third harmonic and a 34 dB suppression for the fifth harmonic are achieved while maintaining the characteristics of a conventional Wilkinson power divider. Based on a 15 dB return-loss criteria, the measured fractional bandwidth is 48%. At an operation frequency of 2.65 GHz, the insertion losses are better than 3.4 dB, the return loss is 27 dB, and the isolation is better than 22 dB.

Design of a dedicated beamline for x-ray microfocusing- and coherence-based techniques at the Advanced Photon Source

A dedicated insertion-device beamline has been designed and is being constructed at the Advanced Photon Source (APS) for development of x-ray microfocusing- and coherence-based techniques and applications. Important parameters considered in this design include preservation of source brilliance and coherence, selectable transverse coherence length and energy bandwidth, high beam angular stability, high order harmonic suppression, quick x-ray energy scan, and accurate and stable x-ray energy. The overall design of this beamline layout and the major beamline components are described. The use of a horizontally deflecting mirror as the first optical component is one of the main features of this beamline design, and the resulting advantages are briefly discussed.