Advanced Materials Research Vols. 986-987

Abstract: Double-fed induction generator has the characteristic that voltage signal output maintain stable with the stable rotate speed, which leads to the wide utility of double-fed induction generator in the area of distributed power generation. In this paper, the basic structure and control method of double-fed induction generator were introduced and emphasis was put on the control technique of grid-side convertor of double-fed interaction power generation system. Simplified model of grid-side convertor was given in the double-fed interaction power generation system. On this basis, the performance was analyzed and control scheme of grid-side convertor was designed. Through Matlab/Simulink, simulation of stable output of DC side voltage was realized.

Abstract: In this paper, the series converters of Distributed Power Flow Controller are the main object of study. Its mechanism of suppressing power system oscillations is studied by theoretical analysis and formula derivation, which relies on a single-machine infinite-bus power system, installed the series converters. Then based on the mechanism, adopting the classic PI control and the damping controller, designed the transient stability control loop for the series converters. Finally, simulations performed by PSCAD/EMTDC, the results show that DPFC device can effectively suppress oscillation and improve system stability.

Abstract: In the high altitude, solar energy, biomass energy and wind energy are widely available and renewable energy sources. It will improve the region's living levels at high altitude and the ecological environment when developed efficiently and in low cost. Making full use of renewable natural resources is of great value and significance to sustain the development of high-altitude areas of the economy. This paper is a kind of research and study, which based on new energy and aims at making full use of solar energy, wind energy, biomass energy complementary relationship and physical changes between planting and breeding to improve the renewable energy industry, integrated, modular for the high altitude area residents gathered .

Abstract: When the grid voltage dips, in order to keep DFIG connected to grid and accelerate the recovery of grid voltage, reactive power compensation STATCOM is adapted to provide reactive power for grid, and crowbar circuit is installed to protect the converter of DIFG. Transient stability of power system is improved and the low voltage ride through is realized.

Abstract: This paper proposed, with the constant speed and variable pitch wind turbine as the research object, and E-Wind Turbine software as simulation platform, S7-1200 PLC as the master controller, the system control module were optimized for selection and configuration,thereby improving system performance and reducing design costs. Finally, in the STEP7 Basic V11 the modules which had been a good selection and configuration were connected, then to complete the configuration of communication, to verify the feasibility of communication and the effectiveness of the system optimize configuration when the wind turbine implemented the simulation in the E-WT platform.

Abstract: In this paper, the rural power low-voltage of Li-Tang mains Trunk line raised the issue of secondary boost more than two groups reactive power compensation solutions, focusing on both the load power load variance method to calculate the location and placement of the regulator boost ratio, using precise moment method and reactive secondary terminal voltage rises method calculates the load side of intelligent reactive compensation on the trunk and installation location and capacity, to achieve the optimum design load tap rural power lines and intelligent var compensator configuration. The program changed in Fushun Li-Tang Trunk line in Li-Jia Transformer substation significantly after the implementation of effective, so that the end of the 31km-long line of power quality standards. Economic operation efficiency is improved.

Abstract: For three-wire three-phase system load imbalance in the system when the current imbalance of power grid, The SVG control strategy which was applied in the unbalanced system was proposed by the paper, and carried on the research and analysis by MATLAB simulation function. The simulation results proved that the control strategy could achieve compensation control requirements,at the same time can effectively restrain the negative sequence current.

Abstract: This paper describes a new genre of Toroidal-CVT system, called the Sphere-Toroidal Continuously Variable Transmission (STCVT), which is derived from the half-toroidal traction drive (TCVT) and introduces its structure and working principle. The torque transfers from the input shaft to the cross-axle universal shaft coupling connected with the driven shaft. By discussing the difference between the torque-transfer, the paper will show the possibility of the application in the vehicle. To conclude, the system has the potential to implement infinite extension for the CVT theoretically.

Abstract: Steel pipe for pipeline have to go through multiple procedure in the whole process, and steel pipe transportation problem exists between the various processes. According to the specific requirements of the workshop environment and control tasks, a new communication mode that use S7-300PLC as the control core, connect 8 DP substation, involve 1077 output and input dot was adopted in the whole system. In the automatic mode, requirements of the complex technological process were realized; shake hands work mode was adopted between the production; using the proximity switch completed the material length measurement; in the location of inconvenience sensor installation, adopted virtual sensor in positioning. The HMI software in PC was WinCC V7.0, and communicated with PLC by Ethernet.

Abstract: Power control technology of LED is proposed, which can be adaptive to the change of temperature while online. The input power of LED will be adjusted according to the current value and its change rate of LED radiator. Reducing input power can balance the decreasing of the capacity of heat dissipation caused by the rise of ambient temperature in order to keep radiator temperature in a safe range. This avoids the vicious circle of the temperature excursion of P-N Junction caused by the rise of the temperature of LED light source characteristic of negative temperature. This, in turn, avoids damage to LED at high temperature.