| Under the dual pressure of the scarcity of resource and contamination of the environment,the technology of wind power has received more attention and is becoming mature gradually.Meantime,an increasing number of the wind power plants have been constructed and put into use,of which the proportion is increasing and the voltage level that are deployed ranges from that of previous distribution network to that of present high-voltage transmission system.Due to the stochastic and unpredictable attribute of the wind,the impact of wind power on the stability of power system is becoming more and more prominent.Given these backgrounds,this dissertation deeply investigations on the impacts of wind farms on power system stability for the reasonable and stable penetrations of wind farms into power system.Meanwhile,the researching work can provide theoretical preparation and technology support for the programming,designing,policy-making and safe operation of wind farms.The main work of the dissertation is listed as follows:(1)In order to analyze the influence of wind power injection on the stability of power system,the wind speed model,wind turbine model and shaft system model of a mechanical transmission system are established.The paper derives the dynamic model of the squirrel-cage induction generator and a doubly-fed induction generator expressed in the reference frame rotating in synchronous speed.and the static equations of the former are deduced according to the assumption of the static process and the static equivalent circuit is constructed.(2)The continuous power flow algorithm of PSASP is applied to obtain the static voltage point of the system.Then the proposed busbar participation factor is used to study the shift of the weak area of the system after the wind power is connected to the grid and the variation rule is finally summarized.The PV analyses is deployed to study the influence of different injection quantities of wind power,electrical intensity of outlets and grid connection parameters on the static voltagestability of the system.(3)The small interference stability analysis module of the PSASP is used to analyze the small signal stability of the system that squirrel-cage asynchronous and doubly-fed induction wind electric field are attached.The Inverse Iterative Rayleigh Quotient Iterative algorithm is used to obtain the eigenvalues of system.Then the eigenvalue analysis method is disposed to analyze the small signal stability of the above to different types of wind electric field in three aspects.(4)The transient stability calculation module of the PSASP is used to study the influence of different types of wind electric field on the transient stability of the power system.During the analysis of the transient stability of wind electric field on power system,this paper manually set the three-phase short-circuit faults to analyze the influence of the different type of the wind electric field on the transient stability of the power system as well as the influence of different capacities,different position and different line parameter on transient stability. |
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