let g be a connected simple (molecular) graph. the distance d(u, v) between two vertices u and v of g is equal to the length of a shortest path that connects u and v. in this paper we compute some distance based topological indices of h-phenylenic nanotorus. at first we obtain an exactformula for the wiener index. as application we calculate the schultz index and modified schultz index of this ...

Reactive power and voltage control is a minimization problem. In this paper the multi objective function consist of minimization of real power losses, minimization of voltage deviation and minimization of voltage stability index subjected to equality and inequality constraints are considered. This can be achieved by proper adjustment of control variables such as the generator voltages, the tran...

Voltage instability is a crucial issue in the secure operation of power grids. Several methods for voltage stability assessment were presented. Some of them are highly computationally intensive, while others are reported not to work properly under all circumstances. This paper proposes a new methodology based on the generator equivalent circuit model (GECM) and the phasor measurement unit (PMU)...

This paper presents a method to control both the dc boost and the ac output voltage of Z-source inverter using neural network controllers. The capacitor voltage of Z-source network has been controlled linearly in order to improve the transient response of the dc boost control of the Z-source inverter. The peak value of the line to line ac output voltage is used to control and keep the ac output...

The paper presents a method for finding out the weakest bus based on reactive power sensitivity index for a multibus real system. The Voltage Stability Margin (VSM) and change in voltage has also been calculated for the verification for with and without compensation. These techniques are tested on the 400 KV WBSEB system proposed in the 9th plan and results are given to prove the effectiveness ...

This article describes the methodology for evaluation of the reliability of an composite electrical power system considering voltage stability and continuation power flow, which takes into account the peak load and steady state stability limit. The voltage stability is obtained for the probable outage of transmission lines and removal of generators along with the combined state probabilities. T...

when power systems are expanded and connected together with weak tie lines, the low-frequency oscillations are increased and the stability margin of the power system decreases. therefore, when designing the transmission system to be used, it is necessary to maintain the dynamic stability of the power system, and to make sure to have the most possible stability margin. sssc is a facts device con...

Abstract With the rapid increase of distributed photovoltaic (DPV) generations, static voltage stability (SVS) distribution network (DN) is faced with more and challenges. Considering characteristics DPV structure, an appropriate index (SVSI) in medium-voltage DN studied this paper. In terms limitation traditional SVSI that only reflects load change, based on P-V curve, a novel change rate - (M...

Silicon nanowires (Si NWs) modified by covalent Si-CH3 functionality, with no intervening oxide, show atmospheric stability, high conductance values, low surface defect levels, and allow for the formation of air-stable Si NW Field-Effect Transistors (FETs) having on-off ratios in excess of 105 over a relatively small gate voltage swing (+/-2 V).