An Active Voltage Coordinate Control Strategy of DFIG-Based Wind Farm with Hybrid Energy Storage System

In a power system with wind farms, the point of common coupling (PCC) usually suffers from voltage instability under large wind speed variations and the load impact. Using the internal converter of a doubly fed induction generator (DFIG)-based wind turbine to provide voltage support auxiliary service is an effective scheme to suppress the voltage fluctuation at PCC. To satisfy the reactive power demand of the connected grid, an active voltage coordinate control strategy with the hybrid energy storage system of the wind farm is proposed. The dynamic reactive power balance model is established to show the interaction between the reactive power limitation of the wind farm and the reactive power compensation demand of the grid. This indicates the initial conditions of the active voltage coordinate control strategy. According to the critical operating point and the operation state of the DFIG, the active and reactive power coordinate control strategy composed of active ω-β coordinate control and active β control is proposed to enhance the reactive power support capability and stabilize the grid voltage. To compensate the active power shortage, an auxiliary control strategy based on the hybrid energy storage system is introduced. The simulation results show that the proposed strategy can suppress the voltage fluctuation effectively and make full use of primary energy.

Development of an information measuring and control system for a quadrocopter

The article deals with the issues of synthesis and analysis of information-measuring and control systems of quadrocopters. The main sensors and modules used to determine the parameters of the coordinates of quadrocopters are given. The speed-controlled electric drives used for control and the features of their choice are considered. The coordinate systems (fixed and mobile) and the kinematic scheme are given, according to which a system of differential equations is presented. The system describes the dynamics of the quadrocopter movement and takes into account the expected smooth movement of the quadrocopter with small roll and pitch angles. A functional scheme and a mathematical model of the information-measuring and control system of the quadrocopter in the form of a block diagram are developed taking into account the influence of delays in the receipt of information from the sensors of the quadrocopter parameters. A special feature of this work is to take into account the specific characteristics of the elements: adjustable electric drives (both direct and alternating current), parameter sensors (barometers, accelerometers, rangefinders, etc.). The paper studies an illustrative algorithm for the operation of the informationmeasuring and control system of the quadcopter. The type and parameters of the controllers of the quadrocopter control systems are determined. Special attention is paid to the settings for the control contours at the corresponding coordinates. The influence of the controllers of the coordinate control systems of the information-measuring and control systems of the quadrocopter on the effects of the interaction of coordinates is considered. The simulation results are presented. The optimal number of control loops for the coordinates of the information-measuring and control systems of the quadrocopter and the optimal type of settings for obtaining smooth transients (without overshoot) and for excluding the interaction of coordinates on quality indicators are determined.

Research and Design on the Coordinate Control System of Once-through Boiler Power Unit

Taking the 1000 MW ultra supercritical unit as an object of study, The nonlinear model is builded through mechanism analysis, which is linearized based on small error, the multi-variable decoupling controller is designed to achieve full decoupling of the input and output variables, and finally the three-input-three-output coordinated control system (CCS) is established. The control system is verified by coal quality and the specific enthalpy of feed water disturbance when load changing, the simulation result shows that the improved CCS has good control performance.

Functionally distinct roles for eEF2K in the control of ribosome availability and p-body abundance

Processing bodies (p-bodies) are a prototypical phase-separated RNA-containing granule. Their abundance is highly dynamic and has been linked to translation. Yet, the molecular mechanisms responsible for coordinate control of the two processes are unclear. Here, we uncover key roles for eEF2 kinase (eEF2K) in the control of ribosome availability and p-body abundance. eEF2K acts on a sole known substrate, eEF2, to inhibit translation. We find that the eEF2K agonist nelfinavir abolishes p-bodies in sensory neurons and impairs translation. To probe the latter, we used cryo-electron microscopy. Nelfinavir stabilizes vacant 80S ribosomes. They contain SERBP1 in place of mRNA and eEF2 in the acceptor site. Phosphorylated eEF2 associates with inactive ribosomes that resist splitting in vitro. Collectively, the data suggest that eEF2K defines a population of inactive ribosomes resistant to recycling and protected from degradation. Thus, eEF2K activity is central to both p-body abundance and ribosome availability in sensory neurons.

Determination of error of sector location of subterrene stabilizing section based on coordinate control data

Results of the study of actual accuracy of the stabilizing section shell of the prototype subterrene are presented. The problem of experimental verification of the assumptions made in modeling is formulated. The research described in the article was carried out on the basis of experimental data obtained by coordinate control of the shell of the prototype subterrene. Data analysis was carried out by mathematical modeling of the surface of the shell of the stabilizing section as a whole and the surfaces of each individual sector. The obtained mathematical models are based on the approximation of sets of points obtained in the process of coordinate control by cylindrical surfaces. The article shows that at least a significant part of the deviations of the geometric shape of the section shell (from 30.3 to 52.3%) is explained by errors in the location of the sectors and errors in their radii. On the basis of the performed modeling, absolute values of the corresponding errors and actual values of the dimensions and deviations were determined. Studies confirmed the possibility of ensuring the specified accuracy of the shell surface when implementing the assembly technology used in a pilot production. At the same time, the proximity of actual deviations to maximum permissible values can lead to problems in ensuring the stable quality of subterrene case products in mass production. Correlation analysis of coordinate control data and statistical analysis of the series of residuals of developed models were carried out. Correlation analysis confirmed the dependence of deviations of experimental points on their cylindrical coordinates, which confirms the significance of the error in the location of the sectors in deviations from the geometric accuracy of the shell.

End-Effector Position Tracking Control for an Aerial Manipulator with a Lightweight Manipulator

An end-effector position tracking control task for an aerial manipulator is usually constituted by two subtasks. The first is motion control, and the second is coordinate control so that the end-effector of the aerial manipulator can precisely track the given trajectory. This paper proposes a novel end-effector position tracking control approach for the aerial manipulator with a lightweight manipulator to achieve these two subtasks. The motion control of the aerial manipulator is solved by a partially coupled approach and divided into a multirotor controller and a manipulator controller. The multirotor controller is designed by the adaptive neural network control, while joints of the manipulator are steered by PID controllers. By resorting to radial basis function neural networks with adaptive weight estimation laws, the dynamic coupling between the multirotor and the manipulator can be compensated in real time. With the support of Lyapunov stability criteria, it is proved that the desired trajectories can be boundedly tracked by the multirotor under the proposed controller. Then, a new coordinate control method is proposed based on the linear model predictive control method. This method ensures that the solution satisfies physical limits of the aerial manipulator and can be executed in real time. Simulations demonstrate that the proposed motion controller significantly outperforms a baseline nonlinear motion controller in the simulation cases. Besides, comparisons among the proposed coordinate control method and traditional methods are simulated to demonstrate effectiveness and performance.