Harmonic Circuit Research Articles

Innovative Approach for the Study of Tuning Circuit with Open Source Tools

In the new age of an online teaching-learning process, present instructional approach expects students to be an active learner, which necessitates a new instructional tool that can provide opportunity for active learning. The use of technology in teaching-learning has become a key factor which helps in conceptual understanding. Simulation being one of the valuable instructional tools renders an opportunity to visualize the concepts and facilitate to build the mental model. The present work proposes a study of electrical circuit experiments performed using open source tools such as XCOS and expEYES. These tools facilitate in developing higher order critical thinking and analysis skill. XCOS being one of the tools in Scilab provides the visual simulation environment for varying the input parameters of the model. The RL, RC, and RLC tuning circuits are virtually modeled by using the XCOS and the real circuits made with expEYES, which facilitates the study of response curves with ease. In the later case, the results obtained by using expEYES compared with the results of XCOS. In addition, the study explains how such response of simple linear circuits can be extended in different applications. Demonstrations and visualization of the response curve and phase flow of linear circuits will overlay the way to understand experimental and numerical results. This innovative approach can be used in the classroom demonstration of a harmonic oscillator and resonant circuits in advance level physics and engineering laboratories.

Optimal nonlinear filtering of M-PSK signals against a background of harmonic interference with a random initial phase

Objectives. The widespread use of radio data transmission systems using signals with multiposition phase shift keying (MPSK) is due to their high noise immunity and the simplicity of constructing the transmitting and receiving parts of the equipment. The conducted studies have shown that the presence of non-fluctuation interference, in particular, harmonic interference, in the radio channel significantly reduces the noise immunity of receiving discrete information. The energy loss in this case, depending on the interference intensity, can range from fractions of dB to 10 db or more. Therefore, interference suppression is an important task for such radio systems. The aim of the work is to synthesize and analyze an algorithm for optimal nonlinear filtering of MPSK signals against a background of harmonic interference with a random initial phase.Methods. The provisions of the theory of optimal nonlinear signal filtering and methods of statistical radio engineering are used.Results. The synthesis and analysis of the algorithm of optimal nonlinear filtering of MPSK signals against the background of harmonic interference with a random initial phase are carried out. The synthesized receiver contains a discrete symbol evaluation unit, two phase-locked frequency circuits of reference generators that form evaluation copies of the signal and interference, and cross-links between them. Analytical expressions are obtained that allow calculating the dependences of the bit error probability on the signal-to-noise ratio and the interference intensity µ. It is established that uncompensated fluctuations of the initial phase of the useful signal have a greater effect on the receiver noise immunity than similar fluctuations of the phase of harmonic interference, especially with low positional signals.Conclusions. Comparison of the obtained results with the results obtained in the case when there are no harmonic interference compensation circuits shows that the use of the obtained phase filtering algorithms allows for almost complete suppression of harmonic interference. Thus, if µ = 0.5 and the probability of error is 10−2, the energy gain at M = 2 is about 2.5 dB, at M = 4 – about 6 dB, at M = 8 and M = 16 – at least 10 dB.

2.4 GHz GaN HEMT Class-F Synchronous Rectifier Using an Independent Second Harmonic Tuning Circuit.

This paper proposes a class-F synchronous rectifier using an independent second harmonic tuning circuit for the power receiver of 2.4 GHz wireless power transmission systems. The synchronous rectifier can be designed by inverting the RF output port to the RF input port of the pre-designed class-F power amplifier based on time reversal duality. The design of the class-F power amplifier deploys an independent second harmonic tuning circuit in the matching networks to individually optimize the impedances of the fundamental and the second harmonic. The synchronous rectifier at the 2.4 GHz frequency is designed and implemented using a 6 W gallium nitride high electron mobility transistor (GaN HEMT). Peak RF-dc conversion efficiency of the rectifier of 69.6% is achieved with a dc output power of about 7.8 W, while the peak drain efficiency of the class-F power amplifier is 72.8%.

Обоснование схемы активного фильтра гармоник на основе гибридного каскадного инвертора

With an increase in the number of levels in the inverter, the circuit becomes more complicated, the number of semiconductor switches increases. Therefore, topologies, which make it possible to obtain an increase in voltage levels with a decrease in the number of semiconductors, to increase the performance and reliability of the system, are of great interest. The paper proposes a scheme of a hybrid cascade inverter, considers a method of pulse-width modulation based on a carrier, and presents a block diagram of an algorithm for generating reference modulating signals in an optimized method of pulse-width modulation. To control a hybrid inverter as part of an active harmonic filter, a method of pulse-width modulation of the carrier is proposed. It allows reducing the common-mode voltage, switching losses, and minimizing current and voltage harmonics. The paper describes the PWM algorithm, on the basis of which the control signals are modulated and then compared with a triangular carrier to generate a sequence of pulses that turn on or turn off semiconductor switches. The purpose of the proposed solutions is to improve harmonic distortion caused by non-linear load in a 0.4 kV low-voltage system. The results of modeling the proposed active harmonic filter circuit are presented. Based on the studies performed, it is shown that the use of an active harmonic filter based on a 5-stage hybrid inverter with pulse-width modulation control is an effective means of filtering higher harmonics on 0.4 kV low voltage buses in the presence of a nonlinear load, which allows solving the problem of eliminating the impact of higher harmonics on the production activities of the enterprise.

A Clamped and Harmonic Injected Class-E Converter With ZVS and Reduced Voltage Stress Over Wide Range of Distance in WPT System

The inherent frequency of magnetic coupling resonance based wireless power transfer system (MCR-WPT) is up to the level of kHz or even MHz. The class-E converter with zero-voltage switching (ZVS) could eliminate the considerable switching loss, however, the high voltage stress and sensitive ZVS condition to coils distance limit its application seriously in MCR-WPT. To solve the issues, a voltage-clamped class-E converter, consisting of an auxiliary clamped circuit to decrease the voltage stress and a harmonic circuit to realize ZVS against a wide range of coils position, is proposed for the WPT system. According to the harmonic analysis, the relationship among duty cycle, input voltage, amplitudes and phases of the harmonics is obtained. Then, the design strategy for system parameters, especially for the harmonic circuit is presented, so that, ZVS could be maintained over a wide range of coils distance. Meanwhile, the efficiency analysis is also carried out, suggesting a steady high efficiency further. Three design examples with disparate harmonic parameters and ZVS ranges are presented and one of the three examples is selected to make comparison with a typical Class-E WPT system. The experimental results agree with the theoretical analysis well.

The spring oscillator model degenerated into the coupled-mode theory by using secular perturbation theory

In the past few decades, although coupled-mode theory (CMT) has been extensively studied in quantum system, atomic system, plasmon system, circuit system, and so on, the theoretical origin is still plaguing many researchers. In the book of waves and fields in optoelectronics, the second-order differential equations of the simplest LC simple harmonic vibration circuit was turned into the first-order differential equation using the method of variable substitution by Haus. However, there is not loss in the simplest LC simple harmonic vibration circuit, loss term is introduced by qualitative analysis. Although this method of dealing with problems has no problems from a physical point of view, it is not rigorous enough from a mathematical point of view. In this paper, based on the secular perturbation theory, the well-known spring oscillator model is degenerated into two-mode CMT. Starting from the second-order differential equations of the spring oscillator model, the secular perturbation theory is used to obtain first order differential equations of two-mode CMT. The results show the relationships between each term’s coefficients in two-mode CMT and the physical quantities in Classical Mechanics are established by using the secular perturbation theory. Through solving two-mode coupled-mode equations, the energy transfer efficiency has been obtained. To verify the correctness of two-mode CMT, we design a coupled tuning fork mechanical vibration system, which consists of two experimental instruments to provide driving force and receive signals, two tuning forks and springs. The amplitude spectra are measured by an experimental instrument of forced vibration and resonance (HZDH4615), which provides a periodic driving signal for the tuning fork. To clarify the mechanism of the spectra, the numerical fitting has been performed by mathematica software based on the energy transfer efficiency. Theoretically, the obtained fitting parameters can also evaluate some important attributes of the system. The theoretical results are in close correspondence with the experiment. That is to say, two-mode CMT is suitable for classical vibration system.This study provides a more rigorous derivation for each term’s origin in two-mode CMT, and has guiding significance in the theoretical research of linear coupled vibration system.

Magnitude-Reshaping Strategy for Harmonic Suppression of VSG-Based Inverter Under Weak Grid

Driven by inertial demand from the grid, the virtual synchronous generators (VSGs) are widely utilized in distributed generation systems. However, harmonic sources in the distributed generation systems with high grid impedance will cause grid voltage distortion. Distorted voltage greatly affects the power quality of VSG. Moreover, it is difficult to suppress different types of harmonics (such as sub-synchronous harmonics and non-integer high-frequency harmonics) by one conventional solution in VSG-based grid-connected system. To solve the problem, this paper proposes a magnitude-reshaping strategy to increase the output impedance in all harmonic-frequency-bands, thereby suppressing the harmonics. The magnitude-reshaping strategy consists of a notch filter and harmonic regulator. The notch filter extracts harmonic components of grid current, whereas the harmonic regulator increases the equivalent harmonic impedance. The equivalent harmonic circuit of reshaped VSG-based system is equivalent to open circuit. Therefore, the power quality of grid-connected current can be guaranteed. To analyze the performance of the magnitude-reshaping method, frequency-coupling impedance model of VSG is established. Furthermore, Comparing with the conventional harmonic suppression methods, the frequency response characteristics of the equivalent harmonic impedance are analyzed. Finally, the effectiveness of proposed control strategy is validated by experiment results.

A 2.5-GHz 1-V High Efficiency CMOS Power Amplifier IC with a Dual-Switching Transistor and Third Harmonic Tuning Technique

This paper presents a 2.5-GHz low-voltage, high-efficiency CMOS power amplifier (PA) IC in 0.18-µm CMOS technology. The combination of a dual-switching transistor (DST) and a third harmonic tuning technique is proposed. The DST effectively improves the gain at the saturation power region when the additional gain extension of the secondary switching transistor compensates for the gain compression of the primary one. To achieve high-efficiency performance, the third harmonic tuning circuit is connected in parallel to the output load. Therefore, the flattened drain current and voltage waveforms are generated, which in turn reduce the overlapping and the dc power consumption significantly. In addition, a 0.5-V back-gate voltage is applied to the primary switching transistor to realize the low-voltage operation. At 1 V of supply voltage, the proposed PA has achieved a power added efficiency (PAE) of 34.5% and a saturated output power of 10.1 dBm.

Harmonic Circuit Self-Assembly in cTAM Models

We explore algorithmic self-assembly models for nanomanufacturing of electronic circuits akin to models for DNA self-assembly. Growth is controlled by thresholding of the energy required for attachments of new components to a growing assembly. We introduce two new families of such systems in one dimension (1D) and 2D, the so-called harmonic self-assemblers that generalize the new circuit tile assembly model (cTAM), and answer fundamental questions about the size and energy distribution of the assembly sequences and their steady state. As an application, we fully resolve the 1D electric circuit ladders.

Single-Phase Active Power Harmonics Filter by Op-Amp Circuits and Power Electronics Devices

This paper introduces a new structure for single-phase Active Power Harmonics Filter (APHF) with the simple and low-cost controller to eliminate harmonics and its side effects on low voltage grid. The proposed APHF includes an accurate harmonic detector circuit, amplifier circuit to trap tiny harmonics, switching driver circuit for precise synchronization, and inverter to create injection current waveform, which is extracted from reference signal. The control circuits are based on electrostatic devices consist of Op-Amp circuits. Fast dynamic, simplicity, low cost, and small size are the main features of Op-Amp circuits that are used in the proposed topology. The aim is removing the all grid harmonic orders in which the proposed APF injects an appropriate current into the grid in parallel way. The proposed control system is smart enough to compensate all range of current harmonics. A prototype is implemented in the power electronics laboratory and it is installed as parallel on a distorted grid by the non-linear load (15 APeak-Peak) to verify the compensating of harmonics. The harmonics are compensated from THD% = 24.48 to THD% = 2.86 and the non-sinusoidal waveform is renovated to sinusoidal waveform by the proposed APHF. The experimental results show a good accurate and high-quality performance.

Application of dynamical system theory in LC harmonic oscillator circuits: A complement tool to the Barkhausen criterion

There are different types of electronic oscillators that have a wide variety of applications in areas such as computing, audio, communication, among others. One of these is the harmonic oscillators that generate an output sinusoidal signal. Due to the advantages of these, this paper proposes a methodology based on an analysis based on the dynamical system theory. This provides undergraduates a useful tool for a better understanding of the harmonic oscillators in order to design and implement accurately this kind of circuits. This tool complements the widely recognized Barkhausen criterion, which is a mathematical condition that must be satisfied by linear feedback oscillators. The analysis based on the dynamical system theory consists of obtaining a state matrix and its eigenvalues from the mathematical model of the oscillator circuits. The eigenvalues are adjusted to get an oscillator system, thus from this way, a set of conditions are derived. These conditions are complementary to those obtained by the Barkhausen criterion.

Harmonic Meter Design Using Arduino

This paper discusses the measurement of harmonic content using arduino which is simulated with proteus software. The components used in this meter harmonic circuit are resistor, capacitor, LCD, microcontroller atmega 328P. Microcontroller works based on voltage source (TR1) and current source (TR2) on proteus software. The voltage and current delivered to the microcontroller will be read and executed according to the program on the microcontroller. The program used in this arduino microcontroller is the C language program. The results obtained from this study Arduino successfully measure the harmonic content and display the measurement results on the LCD.

Class E/F$_3$ Tuned Power Oscillator

This paper proposes a Class E/F $_3$ tuned power oscillator based on the Class E/F $_3$ amplifier. The oscillator has a feedback-loop circuit and starts the oscillation in automatic. In addition, the oscillator achieves zero-voltage switching and zero-voltage derivative switching; therefore, the switching losses are reduced under high oscillation frequency. Moreover, the third harmonic tuned by providing a third harmonic series resonant circuit reduces the switch voltage stress of the mosfet sufficiently. The oscillator was designed, built and tested using an IRFR120Z power mosfet . Under the condition of the input voltage 6.003 V, following results were shown: the measured oscillation frequency was 801.6 kHz, the output power was 0.9075 W, and the power conversion efficiency was 86.24%.

Harmonic Modelling of the Wind Turbine Induction Generator for Dynamic Analysis of Power Quality

Given the increasing integration of wind-based generation systems into the electric grid, efforts have been made to deal with the problem of power quality associated with the intermittent nature of these systems. This paper presents a new modelling approach oriented towards harmonic distortion analysis of the induction machine for wind power applications. The model is developed using companion harmonic circuit modelling, which is a natural approach for analysis of the adverse effects of harmonic distortion in electric power systems, and represents an easier solution method than the well known dynamic harmonic domain, since it solves algebraic equations instead of state-space differential equations. The structure of the companion circuits simplifies both the formulation and solution for power systems with wind-based generation systems. This approach is especially useful for analysis of the harmonic interaction in transient and steady states between the wind power generator and the power system, whose interconnection is made through electronic converters. The proposed model allows us to compute the dynamics of the wind turbine, which are influenced by disturbances such as changes in the wind velocity, voltage fluctuations, electric waveform distortion, and mechanical vibrations, among other factors. Moreover, the cross-coupling between harmonic components at different frequencies is considered. The proposed model represents an integral framework of the electrical and mechanical subsystems of a wind turbine, allowing for analysis of the interactions between them, and understanding power quality degradation behaviour as well as causes and consequences, while also giving useful information on the field of simulation and control. To test the performance of the proposed model, a test power system is used to obtain the behaviour of a wind turbine induction generator in response to typical power quality disturbances, i.e., harmonic distortion, and voltage sags and swells. Then, the dynamics of the variables considering their harmonic interactions are analysed.

Beginnings for Beginners: A Pedagogy for Starting a Prelude

This article presents a method for guiding students in the beginning phase of prelude composition, advancing them to the point where the opening gesture is complete and the rest of the prelude can proceed by maintaining the momentum already acquired. This teaching strategy focuses on the notion of what I term the quadruple gambit, a type of opening gesture often employed by Bach. Each gambit (opening move) is quadruple in its evenly timed presentation of four harmonic stages—stable, unstable, unstable, stable—forming either an underlying harmonic circuit of I–IV(or II)–V(or VII)–I or a harmonic shuttle of I–V(or VII)–V(or VII)–I. The harmonic categories of the circuit and shuttle combine with bass-line categories of pedal, clausula, and cadence to create idiomatic gambits for students to deploy in their compositions. In the first half of this article, I define the characteristics of this type of beginning and give multiple examples. In the second half, I demonstrate how instructors can help students emulate these gestures.

Quantum Emulation of Molecular Force Fields: A Blueprint for a Superconducting Architecture

In this work, we propose a flexible architecture of microwave resonators with tunable couplings to perform quantum simulations of problems from the field of molecular chemistry. The architecture builds on the experience of the D-Wave design, working with nearly harmonic circuits instead of qubits. This architecture, or modifications of it, can be used to emulate molecular processes such as vibronic transitions. Furthermore, we discuss several aspects of these emulations, such as dynamical ranges of the physical parameters, quenching times necessary for diabaticity, and, finally, the possibility of implementing anharmonic corrections to the force fields by exploiting certain nonlinear features of superconducting devices.

A highly linear power amplifier for WLAN**Project supported by the National Natural Science Foundation of China (No. 61201244) and the Natural Science Fund of SUES (No. E1-0501-14-0168).

A three-stage power amplifier (PA) for WLAN application in 2.4-2.5 GHz is presented. The proposed PA employs an adaptive bias circuit to adjust the operating point of the PA to improve the linearity of the PA. Two methods to short the 2nd harmonic circuit are compared in the area of efficiency and gain of the PA. The PA is taped out in the process of 2 μm InGaP/GaAs HBT and is tested by the evaluation board. The measured results show that 31.5 dB power gain and 29.3 dBm P1dB with an associated 40.4% power added efficiency (PAE) under the single tone stimulus. Up to 26.5 dBm output power can be achieved with an error vector magnitude (EVM) of lower than 3% under the 64QAM/OFDM WLAN stimulus.

Based on Delay Compensation System for Shunt Active Power Filter Research

APF harmonic detection is the study of the most important parts of the core , quickly and accurately detect the harmonic current is able to quickly output harmonic compensation circuit current of the premise. Delay compensation system is based on the increase in the method specified time compensation angle , which can accurately detect the harmonic current at the same time , the low-pass filter to minimize the time delay generated by MATLAB simulation, the use of delay compensation system active Filter harmonic Detection and Compensation excellent performance, while ensuring high precision detection and compensation while ensuring at the same time , and fully complete filter real-time functionality .

Analysis and Calculation of Electromagnetic Torque for the Voltage Source Traction Motors

The traction motor installed on the high-speed train is powered by inverter. A large number of harmonics may appear when motor is operating. Then the motor speed generate oscillation and finally the dynamic characteristic is affected in vehicle system. In this paper, relied on the electromagnetism of traction motor, the mechanism about emerging harmonic torque is analyzed. In addition, based on the equivalent circuit, the method of calculating the parameters in harmonic circuit is proposed. Two mathematical formulas are also proposed to obtain the fundamental electromagnetic torque and the harmonic electromagnetic torque on traction motor. The time domain and frequency domain distributions of the torques are gained and analyzed. Finally a calculation example of traction motor harmonic torque was analyzed and calculated, and prepared for further study of harmonic torque impacting on vehicle system dynamic performance.

Control of IMD Asymmetry of CMOS Power Amplifier for Broadband Operation Using Wideband Signal

A fully integrated linear CMOS power amplifier (PA) for the broadband operation is developed for handset applications. This amplifier can handle a wideband signal. To achieve broadband/wideband operation, an analysis of the intermodulation distortion for the asymmetric source in a differential cascode structure is presented. Based on the analysis, the linearization technique using a second harmonic circuit at the gate of the common gate is proposed to reduce the asymmetry. The proposed PA with an on-chip transmission-line transformer, which has a broadband matching characteristic, is fabricated using a 0.18-μm RF CMOS technology. The measurement results show that the sideband asymmetry is less than 0.6 dB for a signal with up to 50-MHz bandwidth, and the peak average power is improved by 1.2 dB within the linearity spec of a 16-QAM 7.5-dB peak-to-average power ratio long-term evolution signal. The PA delivers a power-added efficiency of 36.5%-31.2% and an average output power of 27.5-27.1 dBm under an ACLRE-UTRA of -30.5 dBc for a 50-MHz bandwidth signal across 1.4-2.0-GHz carrier frequency.