Search query: asymmetric cycle harmonic injection

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abstract: Unlike traditional passive harmonic filters, modern active harmonic filters have the following multiple functions: harmonic filtering, damping,isolation and termination, reactive power control for power factor correction and voltage regulation, load balancing, voltage flicker reduction, and/or their combinations. Significant cost reductions in both power semiconductor devices and signal processing devices have inspired manufactures to put active filters on the market. This paper deals with general pure active filters for power conditioning, and specific hybrid active filters for harmonic filtering of three phase diode rectifiers.
author_names: Hirofumi Akagi
title: Active Harmonic Filters
venue: Proceedings of the IEEE
year: 2005

abstract: The interest in variable speed multiphase induction motor drives has substantially increased in recent years and novel proposals show good prospects for industrial implementation in high power applications. The additional degrees of freedom existing in multiphase machines have allowed for new applications with high torque density by current harmonic injection in concentrated winding machines. This paper addresses, for the first time, the bifurcation analysis of a five phase induction motor drive when a third harmonic is injected for torque enhancement purposes. The main focus of this paper is to present a mathematically based study of the nonlinear dynamics of the proposed drive with torque enhancement. The overall bifurcation analysis for both concentrated and distributed winding machines confirms that the harmonic injection provides not only torque enhancement but also more robust controllers. This further advantage offers improved performance of multiphase drives compared to their three phase counterparts.
author_names: Mario Javier Duran

Francisco Salas

Manuel Ruiz Arahal
title: Bifurcation Analysis of Five Phase Induction Motor Drives With Third Harmonic Injection
venue: IEEE Transactions on Industrial Electronics
year: 2008

abstract: It is well known that vacuum tube amplifiers and solid state amplifiers sound different. An important factor accounting for the difference is output harmonic contents. This paper describes a novel analog method to change the harmonic contents of a signal. Based on this method, a transistor amplifier with controllable output harmonics has been built. Performance has been evaluated by both objective measurements and subjective listening.
author_names: Jerry C F Li
title: Using Transistors to Emulate Vacuum Tube Sound Quality Based on Asymmetric Cycle Harmonic Injection Method
venue: 2019 IEEE 8th Global Conference on Consumer Electronics (GCCE)
year: 2019

abstract: Over recent years, the output power of micro inverters [module incorporated inverter (MIC) is progressively pushed to higher levels, following the current photovoltaic (PV) modules market trends. The interleaved Flyback inverter under discontinuous conduction mode of operation (DCM) is an appealing solution for PV applications which are based on MIC technology. This topology provides increased power level for distributed PV generation exploitation with simple control configuration, high efficiency, and reduced filter size. In this paper, the harmonic injection capability is incorporated into the interleaved Flyback inverter for the implementation of an active anti islanding scheme. A suitable technical solution is proposed that bypasses the unfolding H bridge, without affecting the active power generation of the inverter and without requiring any hardware modification. In addition, a mathematical model based on the instantaneous power balance theory is presented, being a powerful analysis tool for inverters operating under complete magnetic discharge such as the Flyback inverter (either conventional or interleaved) under DCM or boundary conduction mode of operation. The proposed model predicts accurately the steady state operational behavior of the Flyback inverter under current harmonic injection, either in grid tied or islanding operation. The proposed technical implementation method and mathematical model are verified through simulation and experimental results. Finally, an anti islanding set up based on the proposed harmonic injection technique is presented and implemented into the Flyback micro inverter. The proposed set up is verified through experimental results on various quality factor values, as well as for weak grid conditions.
author_names: Dionisis Voglitsis

Nick P Papanikolaou

Anastasios Ch Kyritsis
title: Incorporation of Harmonic Injection in an Interleaved Flyback Inverter for the Implementation of an Active Anti Islanding Technique
venue: IEEE Transactions on Power Electronics
year: 2017

abstract: Square wave voltage injection is an effective sensorless control method for permanent magnet synchronous motor drives to achieve zero or low speed operation. However, it faces great challenge in the case of rail transit application where the switching frequency is less than or equal to 500 Hz, which results in rich low order harmonics. In order to improve the performance of high frequency square wave voltage injection method over low switching frequency application, an asymmetric space vector modulation (ASVM) method is proposed, and it makes comparisons between carrier and modulation wave in the 1/4 and 3/4 point of each switching cycle. Compared with space vector modulation, ASVM can significantly reduce the low order sideband and baseband harmonics in the bandpass filter bandwidth. As a result, the position estimation, which is calculated by the filtered current signal, is improved. Moreover, the inverter dead time effect has been compensated as well. With these improvements, the rotor position can be estimated without using low pass filters and its dynamic performance can be enhanced. The experimental results proved the effectiveness of the analysis.
author_names: Hang Zhang

Weiguo Liu

Zhe Chen

Guangzhao Luo

Jianxing Liu

Dongdong Zhao
title: Asymmetric Space Vector Modulation for PMSM Sensorless Drives Based on Square Wave Voltage Injection Method
venue: IEEE Transactions on Industry Applications
year: 2018

abstract: This paper presents an active harmonic elimination method to eliminate any number of specific higher order harmonics of multilevel converters with equal or unequal dc voltages. First, resultant theory is applied to transcendental equations characterizing the harmonic content to eliminate low order harmonics and to determine switching angles for the fundamental frequency switching scheme and a unipolar switching scheme. Next, the residual higher order harmonics are computed and subtracted from the original voltage waveform to eliminate them. The simulation results show that the method can effectively eliminate the specific harmonics, and a low total harmonic distortion (THD) near sine wave is produced. An experimental 11 level H bridge multilevel converter with a field programmable gate array controller is employed to implement the method. The experimental results show that the method does effectively eliminate any number of specific harmonics, and the output voltage waveform has low THD.
author_names: Leon M Tolbert

John N Chiasson
title: Active harmonic elimination for multilevel converters
venue: IEEE Transactions on Power Electronics
year: 2006

abstract: A low jitter, low power LC based injection locked clock multiplier (ILCM) with a digital frequency tracking loop (FTL) is presented. Based on a pulse gating technique, the proposed FTL continuously tunes the oscillator's free running frequency to ensure robust operation across PVT variations. The FTL resolves the race condition existing in injection locked PLLs by decoupling frequency tuning from the injection path, such that the phase locking condition is only determined by the injection path. This paper also introduces an accurate theoretical large signal analysis for phase domain response (PDR) of injection locked oscillators (ILOs) The proposed PDR analysis captures the asymmetric nature of ILO's lock in range, and the impact of frequency error on injection strength and phase noise performance. The proposed architecture and analysis are demonstrated by a prototype fabricated in 65 nm CMOS process with active area of 0.25 mm2. The prototype ILCM generates output clock in the range of 6.75 8.25 GHz by multiplying the reference clock by 64. It achieves superior integrated jitter performance of 190 fsrms, while consuming 2.25 mW power. This translates to an excellent figure of merit (FoM) of 251 dB, which is the best reported high frequency clock multiplier.
author_names: Ahmed Elkholy

Mrunmay Talegaonkar

Tejasvi Anand

Pavan Kumar Hanumolu
title: Design and Analysis of Low Power High Frequency Robust Sub Harmonic Injection Locked Clock Multipliers
venue: IEEE Journal of Solid State Circuits
year: 2015

abstract: Injection locking characteristics of oscillators are derived and a graphical analysis is presented that describes injection pulling in time and frequency domains. An identity obtained from phase and envelope equations is used to express the requisite oscillator nonlinearity and interpret phase noise reduction. The behavior of phase locked oscillators under injection pulling is also formulated.
author_names: Behzad Razavi
title: A study of injection locking and pulling in oscillators
venue: IEEE Journal of Solid State Circuits
year: 2004

abstract: This paper presents a reduced switching frequency active harmonic elimination method (RAHEM) to eliminate any number of specific order harmonics of multilevel converters. First, resultant theory is applied to transcendental equations to eliminate low order harmonics and to determine switching angles for a fundamental frequency switching scheme. Next, based on the number of harmonics to be eliminated, Newton climbing method is applied to transcendental equations to eliminate high order harmonics and to determine switching angles for the fundamental frequency switching scheme. Third, the magnitudes and phases of the residual lower order harmonics are computed, generated, and subtracted from the original voltage waveform to eliminate these low order harmonics. Compared to the active harmonic elimination method (AHEM) which generates square waves to cancel high order harmonics, RAHEM has lower switching frequency. The simulation results show that the method can effectively eliminate all the specific harmonics, and a low total harmonic distortion (THD) near sine wave is produced. An experimental 11 level H bridge multilevel converter with a field programmable gate array controller is employed to experimentally validate the method. The experimental results show that RAHEM does effectively eliminate any number of specific harmonics, and the output voltage waveform has low switching frequency and low THD.
author_names: Zhong Du

Leon M Tolbert

John N Chiasson

Burak Ozpineci
title: Reduced Switching Frequency Active Harmonic Elimination for Multilevel Converters
venue: IEEE Transactions on Industrial Electronics
year: 2008

abstract: Preface Introduction Harmonic Analysis Harmonic Sources The Static Convertor Other Harmonic Sources Harmonic Effects: Within the Power System Interference with Communications Power System Harmonic Measurements Transducers and Data Transmission Standards for the Limitation and Control of Power System Harmonics Harmonic Penetration in A.C. Systems Harmonic Elimination Index.
author_names: Jos Arrillaga

David A Bradley

Pat S Bodger
title: Power System Harmonics
year: 2003