Auxiliary frequency control of a wind turbine generator(WTG) has been widely used to enhance the frequencysecurity of power systems with high penetration of renewableenergy. Previous studies recommend two types of con...Auxiliary frequency control of a wind turbine generator(WTG) has been widely used to enhance the frequencysecurity of power systems with high penetration of renewableenergy. Previous studies recommend two types of control schemes,including frequency droop control and emulated inertia control,which simulate the response characteristics of the synchronousgenerator (SG). This paper plans to further explore the optimalauxiliary frequency control of the wind turbine based on previousresearch. First, it is determined that the virtual inertia control haslittle effect on the maximum rate of change of frequency (MaxROCOF)if the time delay of the control link of WTG is taken intoconsideration. Secondly, if a WTG operates in maximum powerpoint tracking (MPPT) mode and uses the rotor deceleration forfrequency modulation, its optimal auxiliary frequency control willcontain only droop control. Furthermore, if the droop control isproperly delayed, better system frequency response (SFR) willbe obtained. The reason is that coordination between the WTGand SG is important for SFR when the frequency modulationcapability of the WTG is limited. The frequency modulationcapability of the WTG is required to be released more properly.Therefore, when designing optimal auxiliary frequency controlfor the WTG, a better control scheme is worth further study.展开更多
With the increasing wind power penetration in the power system,the auxiliary frequency control(AFC)of wind farm(WF)has been widely used.The traditional system frequency response(SFR)model is not suitable for the wind ...With the increasing wind power penetration in the power system,the auxiliary frequency control(AFC)of wind farm(WF)has been widely used.The traditional system frequency response(SFR)model is not suitable for the wind power generation system due to its poor accuracy and applicability.In this paper,a piecewise reduced-order frequency response(PROFR)model is proposed,and an optimized auxiliary frequency control(O-AFC)scheme of WF based on the P-ROFR model is proposed.Firstly,a full-order frequency response model considering the change in operating point of wind turbine is established to improve the applicability.In order to simplify the fullorder model,a P-ROFR model with second-order structure and high accuracy at each frequency response stage is proposed.Based on the proposed P-ROFR model,the relationship between the frequency response indexes and the auxiliary frequency controller coefficients is expressed explicitly.Then,an OAFC scheme with the derived explicit expression as the optimization objective is proposed in order to improve the frequency support capability on the premise of ensuring the full release of the rotor kinetic energy and the full use of the effect of time delay on frequency regulation.Finally,the effectiveness of the proposed P-ROFR model and the performance of the proposed OAFC scheme are verified by simulation studies.展开更多
Adding the auxiliary frequency control function to the wind turbine generator(WTG)is a solution to the frequency security problem of the power system caused by the replacement of the synchronous generator(SG)by the WT...Adding the auxiliary frequency control function to the wind turbine generator(WTG)is a solution to the frequency security problem of the power system caused by the replacement of the synchronous generator(SG)by the WTG.The auxiliary frequency control using rotor kinetic energy is an economical scheme because the WTG still runs at the maximum power point during normal operation.In this paper,the functional optimization model of the auxiliary frequency control strategy of WTG is established.The optimal auxiliary frequency control strategy is obtained by solving the model numerically.As for the practical realization of the control strategy,the coordination of the auxiliary frequency control with the maximum power point tracking(MPPT)control is studied.The practical auxiliary frequency control strategy is modified to adapt to different power disturbances in the system,and the parameter setting method is also proposed.The sensitivity of system frequency to control parameters is studied.Finally,the simulation results verify the effectiveness and practicability of the proposed control strategy.展开更多
基金the National Natural Science Foundation of China(51922061)the Science and Technology Project of State Grid Corporation of China(SGZJ0000KXJS1900418).
文摘Auxiliary frequency control of a wind turbine generator(WTG) has been widely used to enhance the frequencysecurity of power systems with high penetration of renewableenergy. Previous studies recommend two types of control schemes,including frequency droop control and emulated inertia control,which simulate the response characteristics of the synchronousgenerator (SG). This paper plans to further explore the optimalauxiliary frequency control of the wind turbine based on previousresearch. First, it is determined that the virtual inertia control haslittle effect on the maximum rate of change of frequency (MaxROCOF)if the time delay of the control link of WTG is taken intoconsideration. Secondly, if a WTG operates in maximum powerpoint tracking (MPPT) mode and uses the rotor deceleration forfrequency modulation, its optimal auxiliary frequency control willcontain only droop control. Furthermore, if the droop control isproperly delayed, better system frequency response (SFR) willbe obtained. The reason is that coordination between the WTGand SG is important for SFR when the frequency modulationcapability of the WTG is limited. The frequency modulationcapability of the WTG is required to be released more properly.Therefore, when designing optimal auxiliary frequency controlfor the WTG, a better control scheme is worth further study.
基金supported by the State Grid Corporation Science and Technology Project“Overall process optimization control technology of frequency support for large-scale offshore wind power farm in receiving-end grid”(No.5211DS23000F)。
文摘With the increasing wind power penetration in the power system,the auxiliary frequency control(AFC)of wind farm(WF)has been widely used.The traditional system frequency response(SFR)model is not suitable for the wind power generation system due to its poor accuracy and applicability.In this paper,a piecewise reduced-order frequency response(PROFR)model is proposed,and an optimized auxiliary frequency control(O-AFC)scheme of WF based on the P-ROFR model is proposed.Firstly,a full-order frequency response model considering the change in operating point of wind turbine is established to improve the applicability.In order to simplify the fullorder model,a P-ROFR model with second-order structure and high accuracy at each frequency response stage is proposed.Based on the proposed P-ROFR model,the relationship between the frequency response indexes and the auxiliary frequency controller coefficients is expressed explicitly.Then,an OAFC scheme with the derived explicit expression as the optimization objective is proposed in order to improve the frequency support capability on the premise of ensuring the full release of the rotor kinetic energy and the full use of the effect of time delay on frequency regulation.Finally,the effectiveness of the proposed P-ROFR model and the performance of the proposed OAFC scheme are verified by simulation studies.
基金supported by State Grid Corporation of China(No.52094020006V)。
文摘Adding the auxiliary frequency control function to the wind turbine generator(WTG)is a solution to the frequency security problem of the power system caused by the replacement of the synchronous generator(SG)by the WTG.The auxiliary frequency control using rotor kinetic energy is an economical scheme because the WTG still runs at the maximum power point during normal operation.In this paper,the functional optimization model of the auxiliary frequency control strategy of WTG is established.The optimal auxiliary frequency control strategy is obtained by solving the model numerically.As for the practical realization of the control strategy,the coordination of the auxiliary frequency control with the maximum power point tracking(MPPT)control is studied.The practical auxiliary frequency control strategy is modified to adapt to different power disturbances in the system,and the parameter setting method is also proposed.The sensitivity of system frequency to control parameters is studied.Finally,the simulation results verify the effectiveness and practicability of the proposed control strategy.
文摘随着不确定性可再生能源大规模并网,电网频率特性日益复杂。传统火电机组具有响应时间长、无法准确跟踪指令等问题,亟须利用储能提高火电机组参与自动发电控制(automatic generation control,AGC)调频时的调节性能。首先,针对调频考核规则,建立调频性能指标数学模型,并考虑火储系统出力特性,结合改进层次分析法校正调频子指标权重系数,以此构建以调频性能最优为目标的第一阶段优化模型;在此基础上,为了减少储能荷电状态(state of charge,SOC)越限和深度充放情况,以储能SOC偏差最小为目标构建第二阶段优化模型。仿真验证表明:所提的两阶段调频方法能够提高火储联合系统的调频性能和调频收益,同时有效减少储能深度充放情况和工作寿命损耗,提高储能辅助调频服务的可持续性。
