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.
Subsynchronous control interaction (SSCI) has been observed in several wind farms which consist of doubly-fed induction generators (DFIG) and are radially connected to fixed series compensated transmission line. This paper studies the SSCI characteristics of wind farm consisting of different types of generators including DFIG, permanent magnet synchronous generator (PMSG), and self-excited induction...
A novel virtual voltage control strategy is proposed for modular multilevel converter in order to reduce the quantity of voltage sensors at the terminal. The output voltage of the inverter is obtained through the upper and lower arm currents of the converter and used to trace the reference active and reactive power, respectively. According to the Routh-Hurwitz criterion, the root trajectory of the...
The main ideal of the paper is to design an invariant observer for an activated sludge wastewater treatment process. The invariant observer can measure biomass concentration, substrate concentration and dissolved oxygen concentration with high accuracy and rapidity. The observer presents robust convergence property that is proved by theoretical analysis and numerical simulations (MATLAB).
The nonlinear phenomena of the full-bridge DC/AC converter have been reported enormously as the parameters of the converter vary. This paper studies the stability of the full-bridge converter due to Sinusoidal Pulse Width Modulation (SPWM) process. Modulation index is one of the important indicators of the modulation process which affects the operation mode of SPWM converter directly. The evolution...
This study presents an optimization control strategy to improve the ride-through capability of voltage source converter-based high voltage direct current (VSC-HVDC) systems under unbalanced network conditions. To facilitate simple implementation and flexible operation, the current references are derived and synthesized into one generalized equation that introduces two individually adaptable parameters...
For the ultralow altitude airdrop decline stage, many factors such as actuator nonlinearity, the uncertain atmospheric disturbances and model unknown nonlinearity affect the precision of trajectory tracking, A robust adaptive neural network dynamic surface control method is proposed. The ultra-low altitude airdrop longitudinal dynamics with actuator input nonlinearity is established, the neural network...
This paper investigates the dynamical behavior of a full bridge DC-AC inverter controlled by fixed frequency pulse-width modulation which is widely used in photovoltaic (PV) generation system. The main results are illustrated with the aid of numerical simulations obtained from an accurate non-linear time varying model of the system derived without making any quasi-static approximation. Based on bifurcation...
A dynamic surface controller is proposed to correct for gyroscopic effect from propellers on the motion of large quadrotor. The new control law accounts for adverse effect caused by the gyroscopic effect of propellers that the increased speed leads to high order of oscillation. The proposed controller rapidly converges when reaching the equilibrium point, dramatically improving the convergence speed...
The MAODV (Multicast Ad hoc On-demand Vector routing protocol)shows a smooth performance in light load ad hoc networks. However, packets transmission ratio will decrease continuously with the increasingly scale of multicast group. In this paper we discussed the impact of attacks on MAODV protocol. Based on these analyses, we proposed a routing protocol DMAODV (Distensible Multicast Ad Hoc On Demand)...
This paper presents an optimization control strategy for power control of VSC-HVDC under unbalanced grid voltage conditions. For simple implementation and flexible operation, the current references are derived and synthesized into one generalized equation introducing two individually adaptable parameters. The two parameters can be adapted to eliminate the oscillations of instantaneous active and reactive...
In order to enhance the stability, the control scheme for the wind power generation should have strong robustness. Sliding mode control is powerful to reject disturbance and has good robustness. However, sliding mode control is a fast switching control essentially. While accelerating the speed to reach the sliding surface, it will result in large chattering which can induce high-frequency oscillation...
Due to standard label propagation algorithm does not use the correct posterior probability of each iteration, and the propagation information of labeled data and unlabeled data are not distinguished during the label propagation process, this paper proposes a multi-level label propagation algorithm Based on data reconstruction. It adds the data which is correctly labeled for each iteration into the...
CTMAB-DTPA-bentonite (hexadecyl trimethyl ammonium bromide-diethylene triamine pentaacetic acid-bentonite) was synthesized by placing alkylammonium cation and organic chelating agents onto bentonite. The simultaneous adsorption of organic pollutant (phenol) and heavy metals (Cu2+ and Cd2+) mixed contaminant on CTMAB-DTPA-bentonite was investigated. The CTMAB-DTPA-bentonite showed significant adsorption...
Natural Na-bentonites were modified with an organic chelating agent, sodium diethyldithiocarbamatre (DDTC), to prepare a new adsorbent (DDTC-bentonite) for mixed contaminant (Cu2+, Cd2+ and phenol) removal. The optimal conditions for preparation the DDTC-bentonite were investigated. Moreover, the DDTC-bentonite showed significant adsorption for the mixed contaminant from aqueouss solution. The Langmuir...
It is important and necessary for the colleges and universities to cultivate the consciousness of science and technology innovation and improve the creativities of undergraduates according to the training objectives of the innovative ability of outstanding innovative talents. The construction of the college students science and technology innovation base was introduced mainly, including science and...
all the unnecessary information of data structures and types is removed at the end of compilation. However, the high level information is extremely valuable and necessary for many fields such as debugging, reverse engineering, security etc. Without data structures information, reverse engineering is extremely hard to perform. Unfortunately, even the most advanced techniques and tools for reverse engineering...
In-situ aircraft measurements of CCN(Cloud Condensation Nuclei) of 4 flights under the foggy and hazy weather during the period from September to October are analyzed in Shijiazhuang, China. The Analysis of the vertical distribution, the horizontal distribution and the size distribution of CCN were conducted in this article. According to the expression N=CSk, the CCN spectra can be derived. The fitted...
Human head model is based on anatomy. The simulation is run in the case of two modes, the vertical and rotary usages of mobile phone. The electromagnetic radiation dose of 3G cellular telephone is compared with that of 2G cellular telephone. It shows that the former is far less than the latter.
Considering of there is a static error when the conventional PID controller is appLied to adjust the outputs suitably based on the error rate, according to biological immune adjustment principle and combined with conventional PID, a control system in boiler water level of steam drum is designed in this paper. It can reduce effectively the fluctuation range of the water level and water supply flow...
Based on the change in electrochemical behavior of enzymatic activity induced by organophosphates (OP) compounds, a simple electrochemical method has been developed for investigation of Organophosphates (OP) compounds using acetylcholinesterase (AChE) biosensor. Aniline (AN) and multiwall carbon nanotubes (MWNTs) are modified on the surfuce of glassy carbon electrode(GCE). The electrochemical behavior...
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.