An active power filter (APF) plays an important role in compensating the harmonic component of a nonlinear load current. In this paper, deadbeat control (DBC), which has high performance and fast dynamic response, is used as current controller for APF. improved DBC (Imp_DBC) introduced to suppress adverse effect sampling error enhance interference rejection capability system. The characteristics conventional Imp_DBC are analyzed using transfer functions discrete-time domain. robustness...

The control of brushless dc motors (BLDCMs) is similar to during the noncommutation interval. However, three phases are involved in electromechanical energy conversion commutation interval, making BLDCM a three-phase ac motor A novel analysis method for BLDCMs proposed based on coordinate transformation theory, which used usually. model interval acquired two-phase stationary frame by using Clark transformation. suppressing torque ripple and shortening time obtained. Finally, feasibility...

In this paper, a novel discontinuous pulsewidth modulation (DPWM) strategy for neutral-point-clamped (NPC) three-level converter (TLC) is proposed to reduce the switching loss, common-mode voltage (CMV), and remove dc offset from neutral-point (NP) simultaneously, which named as RCMV_DPWM. Based on space vector diagram with reduced CMV, all clamping modes under RCMV_DPWM are revealed. Then, NP controlled by selecting proper mode. The realization of also discussed. Moreover, performances...

The three phases of brushless dc motor (BLDCM) are involved in energy conversion during the commutation interval. A novel analysis method BLDCM based on coordinate transformation theory is proposed this paper, though popular control three-phase sinusoidal motors, such as induction motors and permanent magnet synchronous motors. intuitive easy to understand compared with circuit solving. Combined voltage vector diagram inverter, reduce torque ripple under low speed (LS_RCTR) high (HS_RCTR)...

In order to reduce switching loss of neutral point clamped three-level inverter (NPC TLI), generally discontinuous pulsewidth modulation (DPWM) is used. But it can result in dc offset and ac ripple on (NP) voltage. So a novel pulse sequence DPWM (NPSDPWM) proposed control NP voltage simultaneously this paper. controlled by choosing proper clamping modes. To avoid unexpected action during changing mode, an improved also presented. The NPSDPWM, traditional previous literature are compared,...

Fast rotating targets such as gimbaled antennas or propeller blades may cause migration through resolution cells (MTRC) of the high-resolution range profile during imaging time, which makes inverse synthetic aperture radar image smeared. To solve this problem, a novel method for fast is proposed in paper. The based on segmental pseudo Keystone transform, designed to realize MTRC correction. realization achieved by employing discrete match Fourier algorithm feasible and simple. Experiments...

For micro-Doppler estimation, an innovative Hilbert–Huang transform (HHT)-based instantaneous frequencies estimator approach designated as weighted average frequency algorithm (WAFA) is proposed in this study. The a smoothing of adjacent with normal rectangular window. After achieving spectrum the signal, and amplitudes are then computed to determine corresponding point on time–frequency space, based which can be finally estimated. This estimation has been successfully applied experimental...

Precession is a key feature for distinguishing warhead from decoys in the missile mid course, and method of extraction target with precession based on micro-Doppler modulation provided this paper. The radar echo model cone simulated by point scattering model, Doppler frequency caused developed. As spread spectrum corresponding to amplitude frequency, utilizing estimate angle. Based characteristics micro-Doppler, 2D reconstruction using inverse Radon transform time-frequency distribution...

For the problem of estimating time-difference-of-arrival (TDOA) radio waves impinging on one or a pair antennas for purpose actively passively locating source communications telemetry signal in presence interfering signals and noise, W. A. Gardner has developed some effective methods, such as CCCC SPECCOA etc. However, it is shown that CCCC, related methods do not apply to moving targets because Doppler shift changes cycle frequencies interest. Two new based cyclic cross-ambiguity (CCA)...

For the problem of estimating time-difference-of-arrival (TDOA) radio waves impinging on one or a pair antennas for purpose actively passively locating source communications telemetry signal in presence interfering signals and noise, W. A. Gardner has developed some effective methods, such as CCCC SPECCOA etc. However, it is shown that CCCC, related methods do not apply to moving targets because Doppler shift changes cycle frequencies interest. Two new based cyclic cross-ambiguity (CCA)...

Human motion characteristics study based on radar is a new technique developed in recent years. This paper firstly analyzes the model of human returns, and then designs an X-band continuous wave for measurement. Experiments measuring have been performed radar. The Doppler features are extracted with time-frequency analysis from actual measured data generated by radar, which verifies validity measurement data.

The acquisition, analysis, and prediction of the radar cross section (RCS) a target have extremely important strategic significance in military.However, RCS values at all azimuths are hardly accessible for non-cooperative targets, due to limitations observation azimuth detection resources.Despite their efforts predict azimuth-dimensional value, traditional methods based on statistical theory fails achieve desired results because sensitivity RCS.To address this problem, an improved neural...

Clutter suppression is a vital problem for Ground Penetrating Radar (GPR) signal process. The clutter algorithm of GPR based on Principal Component Analysis (PCA) concerned with the good adaptability ground irregularity, but there still selecting main components which exist in algorithm. To settle this problem, we define principle matrix inner product at first, and analysis approximate mutual orthogonality surface matrix, target background noise matrix. And then, present method modeling...

Abstract The flexible strain sensor can transform the micro or macro deformation into visual electrical signals for monitoring physiological and motor characteristics of human body. However, current commercial sensors generally have some shortcomings such as large stiffness small range. In this work, a compressive with 3D conductive network was fabricated by using biomacromolecule sericin protein dispersed carbon nanotubes (SSCNTs) material melamine foam (MF) elastic matrix. results showed...

It is beneficial for the recognition and classification of targets to obtain geometrical motional parameters simultaneously. This paper proposes a new method estimate target with precession based on combined feature, which generated by Doppler feature high range resolution from radar-OFDM radar. Expanded Hough transform (EHT) employed establish motion information scatterers. The mainly presents principle estimation angle, posture length. Finally, results simulations anechoic chamber data...

In order to research the econometric model of relationship between foreign trade and economic growth in China, it made an empirical study according sample with corresponding data from 1990 2007 China. The results Granger causality test showed that had growth. unit root time series were stable after 1st difference. cointegration there was a long-term equilibrium If value increases by 1 percent, will increase 0.65 percent. With error correction model, short-term fluctuation would lead change...

Foreign Object Debris (FOD) has severely injured airport or airline personnel damaged equipment in airports. However, echoes from runway and lawn are much stronger than that FOD. Thus efficient detection methods based on the reasonable clutter model precise scattering coefficient. This paper improves Kulemin models to describe backscatter coefficients more exactly. First of all, divided into cells. Employing Ulaby's test data these two terrains, we modify by Least Square (LS) fitting....

This paper focus on parameter estimation of periodic frequency modulated (PFM) signals, which can be observed from phenomena in nature. For example, radar returns scattered a walking person. In this work, method for estimating the period PFM signal is proposed, combines time-frequency distribution (TFD) and cyclic spectrum density (CSD). TFD used to transform nonstationary into stationary one with same while CSD estimate low noise (SNR) ratio case. The properties enable proposed algorithm...

The control of Brushless DC motor is similar to motors during the non-commutation interval, but three phases are involved in electromechanical energy conversion commutation interval. A novel analysis method for proposed by employing three-phase AC coordinate transformation theory. model BLDCM interval acquired two-phase stationary frame using Park transformation. constraints reducing torque ripple and shortening time obtained. Finally, feasibility effectiveness verified experimental results.