Wind energy is one of the most available and exploitable forms of renewable energy. The importancernof wind farm penetration is that it can reduce or replace the existing conventional generators. Thernintegration of wind farm to the existing grid introduces new challenges regarding power systemrnwhich need to be addressed. Among power system stability concerns, voltage stability due to thernintegration of wind farms is the one that considerably affect the grid. rnBy now, Ethiopia has wind energy sources with installed capacity of 324 MW that consist of threernwind farms. Among them the largest operational wind farm is Adama II, which has been consideredrnin this thesis, uses Doubly Fed Induction Generator Wind Turbine (DFIG WT). rnIn this study, Adama II wind farm is aggregated from 102 wind turbines to single turbinernrepresentation. Thus, the dynamic model of DFIG WT has been developed and verified using loadrnflow analysis. And the simplified grid model has been developed also. This model is used to analyzernthe dynamic voltage stability as regards the penetration of Adama II wind farm in Ethiopian existingrnnational grid. The modeling, simulation studies and analysis has been done using Power SystemrnSimulator for Engineering (PSS /E) software. rnThe compliance of the grid code behavior of the wind farm has been investigated based on therndetailed analysis of the contingency scenario of that a bolted symmetrical three-phase fault applied atrnthe point of common coupling (PCC) for 150 ms. After fault clearance, the voltage recovers to 1.032rnp.u at the PCC and within 0.6 second following the fault clearance other buses restored to the superrngrid voltage. The active power output and the reactive power restored to 0.9 of the level availablernimmediately before the fault. The results show that Adama II wind farm integrated to the Ethiopianrnpower grid fulfills the wind grid code requirements in response to the short circuit event. The thesisrnalso analyzes the voltage control capability of Adama II wind farm voltage controller on the powerrnsystem dynamic voltage stability. To study its influence, wind generator equipped with /withoutrnvoltage controller is considered. The voltage at the PCC gradually recovers to 1.038 p.u and 1.059 p.urnwith and without voltage controller respectively after the clearance of short circuit fault .It isrnobserved that the voltage with out voltage control strategy exceeds the normal limit of 1.05 p.u.rnFinally, the analysis of wind farm performance in weak grid has been done . It can be observed thatrnthe voltage on the far end substation bus bar is 0.934 p.u and 1.0639 p.u with low and maximum loadrnrespectively. In this case, the results show that voltages are violated the standard voltage range. rnThe simulation results depict that, the contribution of voltage controller is visible since it enhancesrnthe wind farm capability during the fault as compared with no voltage control is enabled. Therefore,rnthe wind farm is able to fulfill the control characteristic of the controller that can improve powerrnsystem dynamic behavior such as voltage stability as spelt out in international grid codes. And also itrnis recommended that EEP has to implement and equipped with voltage controller for all wind farms.