【正文】 nd Computation, 2020, p. 563. 3. Salman S. K., Teo A. L. I., Investigation into the Estimation of the Critical Clearing Time of a Grid Connected Wind Power Based Embedded Generator, Proceedings of the IEEE/PES transmission and distribution Conference and exhibition 2020, Asia Pacific Pucific, Vol. 11, 2020, p. 975980. 4. Jauch C., S248。 this work consists of 14 buses, 5 generators, 11 loads and 83 branches. The transformers connecting generators to the grid are adjusted accordingly. Wind turbines are the 2 MW machines described above in section 2. Note that the generators do not represent a single machine but a group of strongly coupled generators and for this test system the total power is divided as follow: Table 1. Active power of test system generators Generator N176。rensen P., Norheim I., Rasmussen C. Simulation of the Impact of Wind Power on the Transient Fault Behavior of the Nordic Power System, Electric Power Systems Research, VOL: article in press, available online 24 March, 2020, p. 135144. 5. Federico Milano, Power System Analysis Toolbox Documentation for PSAT version β1, July 9, 2020. 6. Soerensen P., Hansen ., Pedro Andre Carvalho Rosas, Wind Models for Prediction of Power Fluctuations of Wind Farms, J. Wind Eng. Ind. Aerodyn, 2020, 90, p. 13811402. 7. Tang Hong, WuJunling, Zhou Shuangxi, Modeling and Simulation for Small Signal Stability Analysis of Power System Containing Wind Farm, J. Power System Technology, 2020, 28(1), 3841. 8. Hansen ., S248。3 the result is CCT = 187 ms. Fig. 4 shows the speed rotor of all generators in parison for a fault clearing time close to the critical clearing time. Figure 4a. Rotor speed of all generators at t=187 ms Case 2: Variable Speed (DFIG Technology) The fixed speed generator added to Bus 3 is now disconnected and substituted by a doublyfed induction generator (DFIG) having a same power (2MW). Thus, the change in the technology can be considered and analyzed. The analysis of the CCT results in an increased stability limit pared to Case 1 with only fixed speed generators in service. The time increases to CCT = 216 ms as shown in figure 5 .This means, that the transient work stability is enhanced when DFIG are connected instead of fixed speed generator. Figure 5a. Rotor speed of all generators at t=216 ms Figure 5b. Rotor speed of all generators at t=217 ms Table 3. CCT for two types of turbine technology on several buses Bus N176。rensen P., Iov F., Blaabjerg F., Initialisation of GridConnected Wind Turbine Models in PowerSystem Simulations, Wind Engineering, 2020, 27(1), p. 2138. 9. Nandigam K., Chowdhury B. H., Power flow and stability models for induction generators used in wind turbines, IEEE Power Engineering Society General Meeting, 2020, 2, p. 20202020. 10. Hansen A. D., Michalke G., Fault ridethrough capability of DFIG wind turbines, Renewable Energy, 2020, 32, p. 15941610. 11. Ha L. T., Saha T. K., Investigation of Power Loss and Voltage Stability Limits for Large Wind Farm Connections to a Subtransmission Network, Power Engineering Society General Meeting, 2020, 2, p. 22512256. 附件 2：外文原文 （復印件） Impact of Wind Power on the Angular Stability of a Power System Djemai NAIMI1, Tarek BOUKTIR2 1 Department of Electrical Engineering, University of Biskra, Algeria 2 Department of Electrical Engineering, University of Oum El Bouaghi, Alg , Abstract Wind energy conversion systems are very different in nature from conventional generators. Therefore dynamic studies must be addressed in order to integrate wind power into the power system. Angular stability assessment of wind power generator is one of main issues in power system security and operation. The angular stability for the wind power generator is determined by its corresponding Critical Clearing Time (CCT). In this paper, the effect of wind power on the transient fault behavior is investigated by replacing the power ge