Power-flow study

About: Power-flow study is a research topic. Over the lifetime, 8091 publications have been published within this topic receiving 155053 citations. The topic is also known as: load-flow study.

Optimum allocation of reactive power for voltage stability improvement in AC-DC power systems

Abstract: The dependence of the system voltage stability on reactive power distribution forms the basis for reactive power optimisation. The technique attempts to utilise fully the reactive power sources in the system to improve the voltage stability and profile as well as meeting the reactive power requirements at the AC-DC terminals to facilitate the smooth operation of DC links. The method involves successive solution of steady-state power flows and optimisation of reactive power control variables using linear programming techniques. The proposed method has been applied to a few systems and the results obtained on a real-life equivalent 96-bus AC and a two-terminal DC system are presented for illustration.

Speed-up the computing efficiency of power system simulator for engineering-based power system transient stability simulations

Abstract: Power system simulator for engineering (PSS/E) has gained great success in power energy industry for its powerful simulation and analysis functions. Along with market deregulation, power system planning and stability analysis warrants more effective and faster techniques owing to the ever-expanding large-scale interconnection of power networks. Running large-scale system multiple case studies on PSS/E can be computationally very expensive and in some cases, simplifications have to be made in order to obtain some results. PSS/E dynamic simulations are accelerated with EnFuzion-based distributed computing method in this study. This approach is proved to be effective by testing with 39-bus New England power system under ‘N-1’, ‘N-2’ and ‘N-1-1’ contingencies analysis, and re-dispatch after disturbance with optimal power flow. The results show that the simulation process can be speeded up dramatically and the total elapsed time can be reduced proportionally with the increase of computer nodes.

Coordinated Voltage Control in Offshore HVDC Connected Cluster of Wind Power Plants

Abstract: This paper presents a coordinated voltage control scheme (CVCS) for a cluster of offshore wind power plants connected to a voltage-source converter-based high-voltage direct current system. The primary control point of the proposed voltage control scheme is the introduced Pilot bus, which is having the highest short-circuit capacity in the offshore AC grid. The developed CVCS comprehends an optimization algorithm, aiming for minimum active power losses in the offshore grid, to generate voltage reference to the Pilot bus. During the steady-state operation, the Pilot bus voltage is controlled by dispatching reactive power references to each wind turbine (WT) in the wind power plant cluster based on their available reactive power margin and network sensitivity-based participation factors, which are derived from the dV/dQ sensitivity of a WT bus w.r.t. the Pilot bus. This method leads to the minimization of the risk of undesired effects, particularly overvoltage at the terminals of the WT located far away from the AC collector substation, by dispatching lower reactive power references compared with the ones nearer to the substation. In addition, this paper proposes a control strategy for improved voltage ride through capability of WTs for faults in the offshore grid, thus leading to improved dynamic voltage profile in the offshore AC grid.