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This paper presents an ac ripple repression method for neutral-point voltage of three-level inverter system with electrolytic capacitor less. To reduce the volume of three-level inverter system, electrolytic capacitor with huge capacitance is must eliminated from dc-link. In the inverter system applying film capacitors, however, the ac ripple component in neutral-point voltage of dc-link is increased...
This paper addresses the harmonic current control for LCL-filtered Voltage-Source Converters (VSCs) connected to ultra-weak (high-impedance) grids. It is shown that the harmonic current controllers tend to be unstable as the Short-Circuit Ratio (SCR) of the system reduces. An active stabilizing control scheme is thus proposed by feeding back the filter capacitor voltage and the converter-side current...
In this paper, an improved grid voltage modulated control (GVM) with power compensation is proposed for grid-connected voltage inverters when the grid voltage is unbalanced. The objective of the proposed control is to remove the power ripple and to improve current quality. Three power compensation objectives are selected to eliminate the negative sequence components of currents. The modified GVM method...
This paper proposes two methods for optimal design of DC bus reference voltage (Vdcref) and an optimal selection of the shunt active filter (SAF) inductor. The proposed methods help to reduce the filter rating, devices stress and increase the performance of the SAF. An optimal choice of the inductor of the SAF is presented based on the slope calculation of the SAF current which was demonstrated to...
Cyber-Physical Systems (CPS) are composed of computation, networking, and physical processes. Model-based design is a powerful technique to apply mathematical modeling in CPS design. A model of a physical system is the description of variations in some aspects and properties of the system such as motion, velocity, and pressure. The variations of physical quantities such as motion, velocity, and pressure...
In this study, the conventional beamforming (CBF) and the minimum variance distortionless response (MVDR) beamforming with a line hydrophone array mounted on an infinite rigid cylindrical baffle are proposed. Based on decomposing the sound field into a summation of harmonics, a model is introduced to compute the noise cross-spectral matrix in the spherically isotropic noise field. Some design examples...
This paper demonstrates the design of the THz triple-push VCOs using slow-wave effect. The VCOs are implemented by 65nm CMOS process. Slow-wave coplanar waveguides(S-CPW) are applied in the VCO as inductors. Co-simulation results are given in this letter. The VCO using S-CPW consumes 49mW of DC power while generating −9.31 dBm of output power with a phase noise of −80 dBc/Hz at 1MHz offset from a...
In this paper, a broadband fourth-harmonic mixer based on gallium arsenide (GaAs) Schottky barrier diodes working at 80–100GHz is designed. This fourth-harmonic mixer is simulated and attains low conversion loss below 14dB in the whole band. The design process and simulation results are explained in detail.
A Lyapunov approach based homogeneous higher order SM-Controller (HOSMC) is considered here, for grid connected three phases three wires shunt active filter (SAF) via LCL filter. This nonlinear controller is an alternative solution to overcome phase shift caused by a linear controller and a chattering effect caused by a 1st order sliding mode controller that is supposed to be of relative degree 1...
Linear flux switching motor with segmented secondary (LFSMSS) is characterized by two kinds of windings, i.e. the DC field windings and AC armature windings, which are distributed alternately on the mover. LFSMSS is vulnerable to large force ripple. This paper investigates the influence of two design techniques (dummy slot and auxiliary tooth) on the force ripple of LFSMSS. In addition, the simulation...
This study investigates the cell voltages and arm currents in double-star modular multilevel converters (DSMMCs) based on power balance and current tracking control law. DSMMCs have been widely applied to static synchronous compensators, high-voltage direct-current transmission, back-to-back power transfer systems, wind/solar power generation and battery storage systems. The size of capacitors in...
The mathematical model of the experimental stand for vibration damping is described in the article. A vibration table is used as a source of vibration of different frequencies. Asynchronous motors are attached to the vibrating table from below. These motors are frequency-controlled and have eccentric disks on the shafts. Due to imbalance, the motors create a vibration that is transmitted to the upper...
The comparisons of the new offered optimum three-segment and the previously considered five-segment variants of the space vectors switching sequence are continued in values of the first three orders of the n-order integral voltage harmonics factors and in values of the first three orders of some unified indices, the so-called n-order aggregate switchings and integrated voltage harmonics factors. The...
This paper proposed a super-twisting algorithm based sliding mode observer (STA-SMO) for permanent magnet synchronous machine (PMSM) sensorless control, in which voltage-source inverter (VSI) nonlinearity is taken into consideration. A lookup table for online tunning sliding mode coefficients of STA-SMO is obtained based on existing stable conditions. Since mismatch between reference and actual voltage...
The speed and accuracy of harmonic current detection are the important index of active power filter. Due to the low pass filter, the traditional ip-iq algorithm has the disadvantage of slow detection speed. The paper proposes a variable step size LMS/LMF adaptive filter algorithm. The adaptive filter can not only change the step size according to the change of original signal, but also change the...
The traditional fundamental harmonic approximation (FHA) method is not applicable any more in high coupling coefficient WPT system. Instead, the harmonic input impedance and currents are derived and analyzed. Soft switching missing phenomenon may occurs when the coupling coefficient is designed to be in the zones (0.89∼0.93), and (0.99∼1). Simple serial-connected LC filters are introduced to correct...
Nowadays the comfort in passenger transport system is very relevant. One source of noise and vibration is the torque ripple. Torque ripple can be generated by an inappropriate machine control tuning and by the inherent torque ripple of the machine. In permanent magnet machines, the inherent torque ripple is composed by three components: electromagnetic torque, reluctant torque, caused by the winding...
Electric drainage is used to protect devices which are buried underground (such as piping) from the negative effects of DC electric traction induced stray currents. In places where stray currents leave the underground device and return into rails, they contribute to the corrosion of buried devices. Electric drainage is one of the possibilities to minimise these negative effects. Electric drainage...
The ever increase of nonlinear loads in electric distribution networks causes many problems due to the high level of harmonic currents. This paper proposes a new technique for controlling a single phase shunt active power filter based on a selective compensation using the newly developed technique of harmonic control arrays. Simulation results confirm the appropriate selective harmonic compensation...
It is possible to carry out activities related to load profiling, energy consumption estimation, planning, taking new investment decisions, managing voltage and energy quality, system efficiency and loss of line with the evaluation of collected data from smart grid. Therefore, it is important to analyze and forecast the smart grid. Energy efficiency in fast-growing countries like Turkey is an important...
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