Influence of distributed generation systems in the distribution systems can increase the level of short-circuit current. The effectiveness of distributed generation systems is affected by the size, location, type of distributed generation systems technology, and the methods of connecting to distribution systems. Wind turbine system is the examples of distributed generation source. Not only does the using of fault current limiter reduce the pressure on network equipment, but also it can provide a connection to improve the function of the system. There are different types of superconducting fault current limiter, which are made of various superconducting materials and with different designs. Superconducting fault current limiter can be categorized as resistive, inductive and bridge. In this research, the effect of superconducting fault current limiter factors investigated on transient recovery voltage, voltage drop and transient behavior of wind turbine systems based on fixed speed wind turbines, in order to study the behavior of all three types of superconducting fault current limiter that was installed in distributed generation systems. The simulation results show that the transient recovery voltage, the voltage drop and the transient behavior of fixed speed wind turbines have been improved using superconducting fault current limiter تفاصيل المقالة

Reactive power as a utility of ancillary service in restructured environment is supplied by Independent System Operator (ISO). Due to the particular importance of optimal pricing strategy in the power market, the study aims to investigate this problem more closely. To this end, first the problems of restructuring, reactive power generation and its associated costs thereof were reviewed and different types of transmission rights identified. Next, an algorithm was proposed as the selected method for reactive power pricing in terms of Fina g simultaneous Opportunity Cost (OC) at power plants. The pricing method was based on the respective marginal costs as ncial Transmission Rights (FTR) of transmission lines in the presence of the hybrid market model (spot and bilateral) usin well as the optimal power flow and implemented the succession planning method via MATLAB for IEEE 57-buses test system. Comparison of the results obtained from the proposed method (where in capacitors and Static VAR Compensator (SVC) were considered as reactive power generation sources) with those of the current pricing method used in the Iran power grid showed increased earnings due to reactive power investment. تفاصيل المقالة