Dexian Yang

Study on the dynamic simulation of prime mover of a turbine-generator

Aiming at the simulation for the prime mover supplied by thyristor, the principle and the fundamental methods to dynamically simulate the self-balancing characteristics of a turbine are studied in this paper. A new scheme is presented to simulate the characteristics of the prime mover when the generator simulator operates in various conditions. Nonlinear control components are adopted to solve long-existing problem on the simulation of the prime mover. Test results verify that the performance of the proposed scheme has its superiority.

Field studies for transient stability in continuous operation and contingency condition during 3 − Φ short circuit at PCC for grid connected 10MW Kastina wind farm

As a result of worlds energy resources crisis and environment pollution increasingly aggravating, distributed generation (DG) based on renewable energy has become a developmental trend for electric power industry in 21 century. However, DGs are usually affected by natural conditions being not able to output power continuously and steadily, so when large scale wind turbine generators are incorporated into the grid there is likely attendance impact it would bring on electric power system stability. In this investigation, the wind farm connection was done at 33/1 1kV level at Kastina substation located at Northern part of Nigeria. This paper is to establish voltage instability and frequency fluctuation that might be associated with the connection of the wind farm to the existing grid. The DigSILENT Power Factory software was used for modeling and simulation analysis of the studies and the results shows that when wind farm is connected to the grid, large clearance time is required for the fault to be cleared for voltage and frequency to become normalize again as compare with normal grid system. The studies has verified transient stability associated problem due to voltage and frequency stability variation phenomenon during the disconection of both windfarm and the load from the existing grid and is easier to predict in future the setting of protective devices and clearance time.