Applied Mechanics and Materials Vols. 385-386

Abstract: Efficiency is a crucial target in wave power generation. Collection efficiency is the first part in the whole power generation proceeding, which is particularly important. In this paper, six buoys with different radius and different height are selected to look for rational structure for higher efficiency. Force, velocity, absorbed energy and motion tendency are analyzed using simulation. The characteristics on the collection efficiency of buoy have been gotten.

Abstract: The main objective of power flow control for unified power flow controller (UPFC) is to increase the transmission capacity over the existing transmission corridor or line. This paper presents a practical engineering methodology of embedding the power flow control model of UPFC into the commercial software -- power system analysis software package (PSASP) based on its user program interface (UPI) function. In the proposed methodology, the interface currents of UPFC series side and UPFC shunt side between the UPFC device and the network are used to control the transmission line power flow and UPFC bus voltage, respectively. In UPFC series side, the current of UPFC series branch is calculated from the power target equation of the controlled line. In UPFC shunt side, the shunt reactive current of UPFC is used to control the bus voltage. Simulation results on a practical power system show that the proposed methodology can be efficiently applied to the engineering research and analysis of the real power grid with UPFC with good convergence and only one control parameter needed to be prescribed.

Abstract: In view of a serious threat for the transient stability of the power system being caused by the large-scale wind farms integration, and combining with advantages of STATCOM which can quickly restore the fault voltage and fastly, flexibly and smoothly compensate the reactive power, a method is proposed using STATCOM controller of to improve transient stability of the power system integrated by large-scale wind farms. The control strategy of the STATCOM controller uses adaptive double loop control. The role of the device to improvement transient stability of the power system is studied under the condition of serious fault. by simulation comparison with the condition without STATCOM controller installed at the same place. The simulation results show that the STATCOM controller can clearly improve transient stability of the power system integrated by large-scale wind farms.

Abstract: A simulation system of dynamic characteristics of relay protection based on smart substation was exploit in this paper. The necessary information was extracted form SCD configurations file of smart substation and fault recording document, the different frequency of sampled data was transformed and unified, the action process of relay protection equipment is simulated with operating equation and action characteristics which is advance defined or self-defined, the process from normal to fault is reappeared by graphics in this system. The system, which was opening and expansibility, was suitable for reproducing dynamic characteristics of protection in smart substation, also was applicable to develop new principle protection equipment.

Abstract: The 12^th Five-Year Plan requires the power backbone transmission network to be with large particles and high bandwidth. The new technology-OTN can meet the requests. In addition, OTN makes up for the limitation of small particles transmission of SDH and the defects of WDM networking. Cross is the key technology of OTN. OTN electrical, optical and photoelectrical hybrid cross techniques and their advantages and disadvantages are introduced in this paper. At last, three kinds of cross network strategies are put forward to meet the needs of the future development of Power backbone transmission network, which make the theoretical foundation for the construction of the net.

Abstract: Based on complex network theory and network topology modeling, this paper analyses the characteristics of Power Communication Network. The simulation apply two indicators that is connectivity robustness and network performance function to respectively evaluate the impact of failure for network connectivity and communication efficiency in order to identify vulnerabilities in the network. At last, propose one topology optimization algorithm based on the point referral number to optimize the network structure. The fault simulation analysis shows that the algorithm is effective to enhance the ability of the network against deliberate attacks.

Abstract: Maximum power point tracking for wind power generation system fixed step climbing algorithm prone to miscalculation and oscillation shortcomings. Adaptive improved optimal gradient method is put forward to overcome the shortcomings and optimize the existing fixed step climbing algorithm. By Controlling Buck Converter duty radio rapidly match between wind power generation system and load impedance. The simulation result shows that the anti-interference and convergence of the improved hill-climb search algorithm is better than that of the traditional one.

Abstract: The traditional power system stabilizer (PSS) usually configures parameters in off-line circumstances and can’t adapt to the variations of power system operating modes well. Based on the prony algorithm, this paper presents a parameter self-tuning PSS. After identifying the system reduced model, it recognizes the real-time low frequency oscillation characteristics of system based on the online prony and uses the dominant mode frequency to complete self-tuning parameters of PSS. The simulation results in IEEE 4-11 system show that the self-tuning PSS based on prony algorithm can adapt to the variations of power system operating modes and restrain low frequency oscillation system better, then improve the stability of the system.

Abstract: In order to study the effect of attitude for corona inception voltage of AC transmission lines conductors in the altitude areas ranging from 0 to 3000 meters, conducted a series of tests about the corona characteristics of AC six-bundle conductors based on the mobile corona cage at Wuhan, Xining and Haibei respectively. Recorded the number of photons after conductors corona discharge by ultraviolet imaging detector. Conductor corona inception voltages were acquired by the tangent method. The measurement result shows that conductors corona inception voltage decrease with increasing altitude. Corona inception voltage is reduced about 8.12% if altitude rises 1000m. The exponential and linear correction equations suitable for 6 × LGJ-400/50 conductors are introduced. The maximum tolerance is less than 5% and meets the engineering needs.

Abstract: The transmission line corridor will inevitably cross the icing area in China. Icing will influence the corona characteristics of transmission lines. In order to deeply analyze the influence law of the icing to corona loss characteristics, an icing test platform that can be utilized to simulate icing conditions was built. Icing test was done in the corona cage of 1.8m×1.8m×4m. Through changing the conductivity of freezing water and the length of icicle, corona loss of the icing conductor was measured and the surface electric field was also simulated with the software ANSYS. The results show that the length of icicle is an important factor affecting the corona loss of the AC conductor and the conductivity of freezing water on that impact is not obvious. Owing to the icicles, the distortion of the conductor electric field is serious. With the increase of icicle length, conductor corona loss value increases significantly. When the length of icicle increases to about 18mm, the increase of the corona loss value is no longer obvious trending to be saturated . The simulation results coincided with the experimental results very well.