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Changeable sensitivity and safety margin are proposed in this paper, which can avoid the voltage violation according to the operation of the current situation. A simulation test is presented to demonstrate the proposed method can decrease adjusting amounts and restoration time efficiently.

Variable-speed constant-frequency (VSCF) wind farms are gradually becoming a significant proportion of generation in weak grids with constantly increasing penetration rate, and it should certainly take responsibility of the grid frequency and voltage stability. Based on the P-Q performance curve of doubly fed induction generator (DFIG), by introducing static synchronous compensator (STATCOM), this paper presents a coordinated control strategy of active power and reactive power to deal with fault and load disturbance in weak grids. Simulation results show that the proposed coordinated control strategy can effectively improve the frequency and voltage stability of the grids.

Wind energy source has been paid high attention to and developed into one of the most mature and largest-scale mode of new energy power generation. However, the uncertainty and fluctuation of wind power brings great challenge to the normal operation of power system. In this paper, the dynamic economic dispatch of wind power incorporated system is demonstrated. The accumulation variable method based on chance constraint programming is adopted to make the dynamic economic dispatch. The test example shows that the accumulation variable method based on chance constraint programming is suitable and effective.

In this paper, a flexure hinge micro-displacement magnifying mechanism was designed, which was based on the principles of triangle amplification, and the amplifier was driven by piezoelectric stack. The displacement of piezoelectric stack was amplified by the flexure hinges micro-displacement magnifying mechanism. In order to test the static and dynamic carried on it. Not only the characteristics of good linearity, magnification, high positioning resolution and high frequency response achieved but also the design theory approved its correctness in the experiment.

Feedforward PID control of the current loop and speed loop based on the three closed loop PID servo control system was introduced here to improve the intermittent rotary positioning performance of the pick-and-place system. Feedforward PID control [1] is better than traditional PID control on command signal tracking under high-speed positioning control, which has been proved by Simulink simulation.

This study explores the effects of the SiO2/Na2O molar ratio (1.0-2.0) on the properties of 1% nanoSiO2metakaolin-based geopolymers. The porosity, flexural strength, DTA/ TGA, and NMR are investigated to study the mechanical and microstructure properties of the geopolymers. The results show that the flexural strength increased, and that the products of geopolymerization filled pores with curing time, causing the microstructure to become denser. Moreover, a nanoSiO2metakaolin-based geopolymer sample with a SiO2/Na2O ratio of 1.5 exhibited more strength and less porosity. Applying the 1% nanoSiO2to a geopolymer enhances compactness, improves uniformity, and increases strength.

Amino-functionalized mesoporous silica (AFMS) with high amino loading, high surface area, and large pore size was synthesized using the anionic surfactant N-lauroylsarcosine sodium (Sar-Na) as template and 3-aminopropyltriethoxysilane (APTES) as co-structure directing agent (CSDA). The synthesized AFMS was characterized by N2adsorption-desorption, TEM and elemental analyzer. The results of the removal of Cd2+from aqueous solution showed that the pH value of aqueous solution affected the removal efficiency of Cd2+greatly, and that unary adsorption isotherm of Cd2+on the AFMS was well described by the Sips isotherm model, in which the adsorption capacity was 2.43 mmol/g for Cd2+, much higher than the literature data.

One kind of new electronic governor is developed on the foundation of the injection pump matched on the YC2118 diesel engine. A single-chip microcomputer is used for core hardware architecture and fuzzy control algorithm for software. The governor has been manufactured out and the test of its performance has been carried on