An electrical power system (EPS) is subject to unexpected events that might cause the outage of elements such as transformers, generators, and transmission lines. For this reason, EPS should be able withstand failure one these without changing its operational characteristics; operativity functionality called N−1 contingency. This paper proposes a methodology for optimal location sizing parallel...

Voltage stability is an important issue in the planning and operation of deregulated power systems. The voltage stability problems is a most challenging one for the system operators in deregulated power systems because of the intense use of transmission line capabilities and poor regulation in market environment. This article addresses the congestion management problem avoiding offline transmis...

Voltage source inverters (VSIs) are usually used for all kinds of distributed generation interfaces in a microgrid. It’s the microgrid’s superiority to power the local loads continuously when the utility fails. When in islanded mode the voltage and frequency of the microgrid are determined by the VSIs, therefore the power quality can be deteriorated under unbalanced and nonlinear loads. A volta...

Power system must be operated in such a way that both real and reactive powers are optimized simultaneously. Reactive powers should be optimized to provide better voltage profile as well as to reduce system losses. The four objectives of minimization of fuel cost, minimization of emission, minimization of losses and increasing stability by minimizing system stability index, these are conflictin...

In a de-regulated open access environment, reactive power is one of the ancillary services which must be provided by an Independent System Operator (ISO). In this paper, a new algorithm is proposed in which reactive power resources are initially so tuned that optimum security in terms of voltage profile and voltage stability are achieved while at the same time, the system losses are minimized. ...

Based on reactive power-voltage characteristics analysis of air conditioners, the effects of air conditioner load on voltage stability of an urban power system are investigated in this paper. Indexes for evaluating bus voltage security are proposed, and static voltage stability analysis method is adopted. The computational analysis of a real urban power system in East China shows that air condi...

This paper suggests a new control method to modify the virtual impedance performance in unbalanced conditions. The proposed method compensates the voltage drop that occurred due to the virtual impedance and adjusts the voltage of the point of common coupling at a desirable level. To compensate the voltage drop, the reference voltage in the droop control varies according to the proposed algorith...

Power system planning and operation in present day are more in favour of economic factors and less in terms of technical aspects such as: system security, reliability and stability analysis. Case in point being: the generator scheduling or the pattern in load sharing among the various generators forms a major part in power system planning. Scheduling primarily based on economic criteria, essent...