The impacts of large-scale grid-connected wind farm on direct-driven permanent magnet synchronous generator(PMSG)type are discussed on the small signal stability performances of power systems.Firstly,a simplified prac...The impacts of large-scale grid-connected wind farm on direct-driven permanent magnet synchronous generator(PMSG)type are discussed on the small signal stability performances of power systems.Firstly,a simplified practical model of wind farm of PMSG type is derived for analyzing small signal stability.The rotor-fluxoriented control strategy is applied to the modelling of PMSG.Secondly,the framework of small signal stability analysis incorporating wind farm of PMSG type is built.Finally,the different simulation scenarios based on the IEEE 3-generator-9-bus test system as benchmark are designed to conduct the eigenvalue analysis and to assess the impacts of wind farm of PMSG type on power system small signal stability.Some conclusions are drawn with simulation results.展开更多
A simulation system for power grid with concentrated large-scale wind farm integration is established based on the electro-magnetic transient model of wind turbine equipped with doubly-fed induction generator (DFIG),w...A simulation system for power grid with concentrated large-scale wind farm integration is established based on the electro-magnetic transient model of wind turbine equipped with doubly-fed induction generator (DFIG),which is built by real-time digital simulator (RTDS).Using the hardware communication interface of RTDS,a closed-loop testing experiment is accomplished to study the impacts of large-scale wind farms on the existing relay protection devices for wind farm outgoing transmission line.This paper points out problems existing in current relay protection devices as follows:fault phase selector can select unwanted phase due to the changes of fault features caused by special network connection of wind farms;blocking condition for distance protections needs to be re-examined due to the weak power-feed characteristics of wind farms;and power frequency parameter based relay protection devices cannot accurately operate due to the special transient voltage and current characteristics of wind farms during fault period.Results lay the foundation for improving the performances of the existing relay protection device and developing new principle relay protection.展开更多
As the penetration of wind power into power grids increases,higher demands are made on the stability and protection of power systems.Unlike traditional synchronous generators,wind turbines are different on the short-c...As the penetration of wind power into power grids increases,higher demands are made on the stability and protection of power systems.Unlike traditional synchronous generators,wind turbines are different on the short-circuit and impedance characteristics,thus some problems exist in pilot protections of transmission lines connecting wind farms.When a single-phase fault occurs on a transmission line,the phase selector based on current-difference sudden-change may mistake the single-phase fault for a phase-to-phase fault.This paper studies the impedance characteristics of an asynchronous wind generator,and analyzes the behavior of a fault phase selector under different conditions.Then,the paper explains that inequality between positive and negative branch coefficients is the cause for the mal-operation of the fault phase selector.Finally,some simulations are done in MATLAB to validate analysis results.展开更多
Nowadays wind energy is the fastest growing renewable energy resource in the world.The problems of integrating wind farms are caused by changes of wind speed during a day.Moreover,the behaviors of wind turbines equipp...Nowadays wind energy is the fastest growing renewable energy resource in the world.The problems of integrating wind farms are caused by changes of wind speed during a day.Moreover,the behaviors of wind turbines equipped with doubly-fed induction generators differ fundamentally from synchronous generators.Therefore,more considerations are needed to analyze the performances of the distance protection relays.The protection of a wind farm with distance relay is inspected.By changing the conditions of the wind farm,the characteristics of the distance relay are studied.展开更多
基金supported by Research Project of Science and Technology from Shenzhen Government of China(No.JC200903180528A)
文摘The impacts of large-scale grid-connected wind farm on direct-driven permanent magnet synchronous generator(PMSG)type are discussed on the small signal stability performances of power systems.Firstly,a simplified practical model of wind farm of PMSG type is derived for analyzing small signal stability.The rotor-fluxoriented control strategy is applied to the modelling of PMSG.Secondly,the framework of small signal stability analysis incorporating wind farm of PMSG type is built.Finally,the different simulation scenarios based on the IEEE 3-generator-9-bus test system as benchmark are designed to conduct the eigenvalue analysis and to assess the impacts of wind farm of PMSG type on power system small signal stability.Some conclusions are drawn with simulation results.
基金supported by the Special Fund of the National Basic Research Program of China (973 Program) (No.2009CB219704)
文摘A simulation system for power grid with concentrated large-scale wind farm integration is established based on the electro-magnetic transient model of wind turbine equipped with doubly-fed induction generator (DFIG),which is built by real-time digital simulator (RTDS).Using the hardware communication interface of RTDS,a closed-loop testing experiment is accomplished to study the impacts of large-scale wind farms on the existing relay protection devices for wind farm outgoing transmission line.This paper points out problems existing in current relay protection devices as follows:fault phase selector can select unwanted phase due to the changes of fault features caused by special network connection of wind farms;blocking condition for distance protections needs to be re-examined due to the weak power-feed characteristics of wind farms;and power frequency parameter based relay protection devices cannot accurately operate due to the special transient voltage and current characteristics of wind farms during fault period.Results lay the foundation for improving the performances of the existing relay protection device and developing new principle relay protection.
基金supported by National Basic Research Program of China(No.2009CB219704)National Natural Science Foundation of China (No. 50977061)National Natural Science Foundation of Tianjin City (No. 11JCYBJC07600)
文摘As the penetration of wind power into power grids increases,higher demands are made on the stability and protection of power systems.Unlike traditional synchronous generators,wind turbines are different on the short-circuit and impedance characteristics,thus some problems exist in pilot protections of transmission lines connecting wind farms.When a single-phase fault occurs on a transmission line,the phase selector based on current-difference sudden-change may mistake the single-phase fault for a phase-to-phase fault.This paper studies the impedance characteristics of an asynchronous wind generator,and analyzes the behavior of a fault phase selector under different conditions.Then,the paper explains that inequality between positive and negative branch coefficients is the cause for the mal-operation of the fault phase selector.Finally,some simulations are done in MATLAB to validate analysis results.
文摘Nowadays wind energy is the fastest growing renewable energy resource in the world.The problems of integrating wind farms are caused by changes of wind speed during a day.Moreover,the behaviors of wind turbines equipped with doubly-fed induction generators differ fundamentally from synchronous generators.Therefore,more considerations are needed to analyze the performances of the distance protection relays.The protection of a wind farm with distance relay is inspected.By changing the conditions of the wind farm,the characteristics of the distance relay are studied.
