Analysis Of The Influence Of Doubly-fed Wind Power Integration On The System's Transient Power Angle Stability

In recent years,sustainable development has become increasingly imminent,and society ’s demand and dependence on energy are also increasing.It is necessary to vigorously develop new energy sources to solve the energy crisis and improve the living environment.As one of the renewable clean energy sources,wind energy has good development prospects,and wind power generation with new power generation technology has received great attention in recent years.As the rapid economic development becomes more dependent on electrical energy,the scale of the power system continues to increase,and the proportion of wind power generation is also increasing.The large-scale integration of wind turbines into the power system will inevitably affect the transient stability of the power system.Therefore,an in-depth study on the impact of the wind turbine access system on the transient stability of the system is urgently needed.In view of the above,this paper studies the effect of the doubly-fed induction generator access system on the transient power angle stability of the system.Based on the transient characteristics of the doubly-fed induction generator,the doubly-fed induction generator is equivalent for research purposes.The impedance equivalent model of the fan and the equivalent model of the controlled current source are used to analyze the influence of the double-fed induction generator connected system on the transient power angle stability of the system.The main research contents of this article are as follows:Influence of Doubly-Fed induction generator Accession on Transient Power Angle Stability of System under Symmetrical Fault..Taking an extended single-machine infinite system with a doubly-fed induction generator as an example,an equivalent model of the doubly-fed induction generator impedance was established,and the analytical formula for the critical clearing angle of the system after wind power was introduced was derived in detail based on the equal area rule.With the change trend of the four influencing factors such as the proportion of wind power,the grid-connected position of the wind turbine,the fault location,and the load access position,the influence of the above four factors on the stability of the transient power angle is summarized law.In PSD-BPA,a simulation model of an extended single-machine infinity system with a doubly-fed induction generator under a symmetric fault is established,and the correctness of the theoretical analysis is simulated and verified.At the same time,an IEEE9 node system with a double-fed induction generator is also established,and a simulation analysis considering the above four factors is performed.Effect of Doubly-Fed induction generator Accession on Transient Power Angle Stability of System Under Asymmetric Fault.In an extended single-machine infinity system with a double-fed induction generator,based on the impedance equivalent model of the double-fed induction generator,the double-fed induction generator is connected to the system according to the equal area rule,and when the system has an asymmetric fault,four factors are considered to affect the system The influence law of the critical clearing angle and the applicability of the influence law to different doubly-fed induction generator models.A simulation model of an extended single-machine infinite system with a double-fed induction generator is established in PSD-BPA,and the correctness of the theoretical analysis is simulated and verified.At the same time,an IEEE9 node system with a double-fed induction generator is also established,and a simulation analysis considering the above four factors is performed.Effect of doubly-fed wind power participating in system frequency modulation on system transient power angle stability.The double-fed induction generator is equivalent to a controlled current source model,taking into account the four influencing factors of wind power ratio,wind turbine grid connection location,fault location,and load access location.The method of quantitative analysis and simulation verification is used,and the equal area rule is used.The theoretical calculation of the critical clearing angle of the system with and without the fan participating in the system frequency modulation is performed,and a simulation model of the extended dual-machine system with a double-fed induction generator is built in the PSD-BPA to verify the correctness of the theoretical analysis.At the same time,the simulation model of the IEEE9 node system with double-fed induction generator and the actual system of Yunnan Power Grid was established,and the influence of the frequency modulation of the double-fed induction generator in the system on the transient power angle stability of the system was simulated and analyzed.