Yao Shujun

Distribution network reconfiguration with distributed power based on genetic algorithm

This paper focuses on distributed power(DG) impact on distribution network and distribution network reconfiguration algorithms. First the article describes the impact of DG on distribution networks failure reconfiguration, Then set reconfiguration evaluation model based on Wind turbine as a specific DG, based on the above, adjust the fitness function structure of Improved genetic algorithm. Meanwhile, this selection operator using the tournament selection method combined with elitist selection method approach in order to make the Selection operator of genetic algorithm focus on the fitness value compared and keep high fitness individuals. Finally, test examples show that the algorithm is reasonable and effective.

Cornish-fisher expansion for probabilistic power flow of the distribution system with wind energy system

DG based on wind energy system (WES) has the probabilisti c output power relied on natural conditions, the traditional deterministic load flow is not a suitable tool for the analyzing and maintaining distribution system. Aiming at this problem, this paper applies a probabilistic power flow (PLF) method to evaluate the influence of distributed generation with WES. Firstly, the probabilistic model of WES is established which considers the relationship between output power of WES and wind velocity. Secondly, instead of the conventional Gram-Charlier expansion, the model of combined cumulant and Cornish-Fisher expansion is applied to calculate the PLF. This model has the more convergence for on-Gaussian probabilistic density function. Lastly, the IEEE 34 distribution system with the modification by injecting the WES to some nodes is tested. The results show that the method in this paper is efficient and reasonable.

A novel transfer switching strategy of solid static for duplex feeding

Voltage sag has become the main culprit to high quality power supply. Solid Static Transfer Switch (SSTS) for duplex feeding is a kind of power device which can effectively alleviate the voltage sags. SSTS will switch sensitive loads to the alternate source with better power quality when the preferred source is suffering voltage sags or interruption. In this paper, the operational principle of SSTS is introduced at first. The dq transfer + low frequency pass filter will be employed for voltage sag detection. The detection technique finds a balance between the fast response and robustness. Authors will give a novel switching technique to speed up the switching performance based on forced commutating and thyristor voltage detection. Finally, the validity and efficiency of the strategy is verified by using the electromagnetic transients simulation. The switching period can be limited within 5 ms which will not cause malfunction of sensitive loads.