The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Phase-locked loops (PLLs) are very important in power and energy areas. Many PLLs have been proposed in recent literatures, and all these methods are to design a robust filter and let them be as a preprocessing tool before the synchronous reference frame PLL (SRF-PLL) input. Among these PLLs, a interesting PLL is Least-Error Squares (LES) Filter-Based PLL (LES-PLL), which is composed of a LES filter...
This paper discusses the harmonics compensation of the constant dc-capacitor voltage-control (CDCVC)-based strategy of smart charger (SC) for electric vehicles (EVs) in single-phase three-wire distribution feeders (SPTWDFs) under the distorted source voltage and load currents conditions. The basic principle of the CDCVC-based harmonics compensation strategy under the distorted source voltage and load...
In this paper, a novel filter structure is proposed based on the sequence of PWM voltage harmonics. At first, the phase of voltage harmonics is thoroughly analyzed. Based on the phase difference between three phases, it is shown that the sideband harmonics can be divided into positive-sequence, negative-sequence and zero-sequence components. Through 120° interleaving and three paralleled converters,...
In this digest, a coupling coefficient estimation method for wireless charging system is proposed based on its transmitter and receiver current and voltage harmonics analysis. One of the main challenges of wireless charging in vehicular application is the significant variation of magnetic coupling coefficient between transmitter (Tx) and receiver (Rx) coils due to large air-gap and lateral misalignment...
In a magnetically coupled resonant (MCR) wireless power transfer (WPT) system, adding repeating coils is an effective way to lengthen transmission distance and improve the transferred power in a wide range. This paper investigated a 3-coil MCR WPT system. Based on fundamental harmonic analysis on the equivalent circuit model, the relationship between the transmission characteristics and the spatial...
To address the active power feeding issue in the parallel Uninterruptible Power Supply (UPS) system, a DC-link Voltage Protection (DCVP) control strategy is proposed in this paper. The proposed control method only relies on local load information, which increases the system reliability and robustness. Moreover, virtual resistance based regulation strategies are proposed for solving the active power...
This paper investigates the torque production and the torque ripple reduction of 6-stator/7-rotor-pole (6/7) variable flux reluctance machine (VFRM). Based on the harmonic analysis, the instantaneous torque equation is firstly derived by considering the spectra of the armature inductance and current. The average torque is found to be mainly produced by the mutual inductances between the field and...
In this paper, a cost-effective and reliable equivalent series resistance (ESR) estimation method for aluminium electrolytic capacitors used as DC-link capacitors in front-end rectifier fed inverters is proposed. The proposed method is based on the extraction of switching frequency components of DC-link voltage and current using band-pass filters. A limiting value of switching frequency is identified,...
This paper presents a novel control method that enables operation of Modular Multilevel Converters under non-sinusoidal AC supply conditions based on frequency domain decomposition of supply voltages. The proposed control method enables to inject or draw near sinusoidal grid currents even during the presence of harmonic distortions in the supply voltages without the use of additional hardware filters...
This paper presents a design methodology with uncertainty quantification to estimate the required margin for two main design variables in a modular multilevel converter (MMC). In this methodology, the minimum required design margins are calculated by quantifying all sources of uncertainty in the modeling and simulation of MMCs. To this end, an enhanced modeling framework is presented to take into...
The modular multilevel converter (MMC), is widely adopted in high voltage applications because of its simplicity and modularity. However, the current and power flow is very complicated. As a result, methods proposed for capacitor reduction, which is required to stored line frequency related circulating energy, all went through complicated mathematical derivation. C. Li proposed a state plane analysis...
This paper presents the theoretical analysis on the errors in voltage synthesis and position estimation due to the voltage distortion in position-sensorless operation. Especially, the pulsating square wave signal injection method into the estimated d-axis would be focused on, revealing the nature that the position estimation performance depends on the frequency of the injected signal. From the analysis,...
In this paper, we investigate the variation in characteristics of variable speed induction motors fed by inverters with grades of core materials used for stators and rotors from both results of measurement and finite element analysis. Identical shaped stator/rotor cores are manufactured by using several kinds of electrical steel sheets from low to high grades. Then, the characteristics of these motors...
Multilevel inverters are high voltage, high power devices with wide electrical applications due to their lower output harmonic component and device stress management capabilities. Manifold control strategies have been proposed and implemented for MLIs and fundamental frequency switching strategies are especially suited due to their ability to provide for higher efficiency. This paper proposes a hybrid...
Neutral point potential oscillation at low frequency is an important issue in four pole neutral point clamped converter since this leads to the extra voltage stress on the split DC-link capacitors. The detailed analysis indicates such oscillation is closely associated with the neutral point current at low frequency, so this paper explores their relationship, and presents the modulation techniques...
Since the capacitor equivalent series resistance (ESR) above 1kHz almost stays constant, dc-link current root-mean-square (RMS) closed form equation is an easy way to evaluate the capacitor losses from the switching harmonic currents (SHCs). But when the ac current contains multiple low order harmonics (LOHs), their impacts on the dc-link has not been systematically studied. In this paper, a straightforward...
In this paper a control system for shunt active power filters based on an array of proportional-resonant regulators is developed. An important advantage of this topology is the possibility of selective control, namely the possibility to choose the set of current harmonics that has to be compensated. The main contribution of the paper is an algorithm that adaptively changes the voltage saturation of...
Modular multilevel converter (MMC) has been proved a prospective topology in high voltage and high power occasions. Hybrid MMC mixed with half-bridge (HB) and full-bridge submodules (FBSMs), which achieves a good tradeoff between power devices quantity and dc short circuit fault handling capability, attracts extensive attention. In this paper, the characteristics of SM capacitor voltage ripples are...
In this paper, we investigate rotor and stator designs of interior permanent synchronous motors for variable speed/load applications to reduce the carrier harmonic losses caused by pulse width modulated inverters. The rotor core and magnet shapes are determined by an automatic optimization method using electromagnetic field analysis that considers the inverter carrier. Appropriate stator-winding configurations...
This paper presents new constraints for Selective Harmonic Elimination (SHE)-PWM technique utilized in single phase applications. The proposed constraints eliminate all triplen harmonic orders naturally whereas they appear in all single-phase output voltage waveforms conventionally. The specified non-triplen harmonics are also eliminated through calculation of switching angles. Five-level high switching...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.