Integration of inverter-based resources(IBRs)reshapes conventional power swing patterns,challenging the operation of legacy power swing protec-tion schemes.This paper highlights the significant con-sequences of the di...Integration of inverter-based resources(IBRs)reshapes conventional power swing patterns,challenging the operation of legacy power swing protec-tion schemes.This paper highlights the significant con-sequences of the distinctive power swing patterns exhib-ited by grid-forming IBRs(GFM-IBRs).The swing mechanism involving GFM-IBRs is elucidated using an-alytical modeling of GFM-IBRs with various power syn-chronization loops(PSLs).With varying GFM-IBR pen-etration levels and different generator scenarios,the per-formance of power swing protection functions is examined,including power swing blocking(PSB)and out-of-step tripping(OST).Additionally,the IEEE PSRC D29 test system is employed to present power swing protection results in a large-scale power system integrated with synchronous generators(SGs)and IBRs.The results in-dicate that,GFM-IBRs with sufficient voltage support capability can provide positive impact on power swing dynamics,and power swing protection performance can be enhanced by emulating the inertia and droop mecha-nism of SGs and rapidly adjusting the active power output.However,with high penetration levels of GFM-IBRs,OST maloperation may occur in scenarios with inadequate voltage support capability.展开更多
A challenge faced by protection and planning engineers is the development and validation of accurate wind turbine generator(WTG)models to study the impact of increasing wind integration on system protection.Thispaper ...A challenge faced by protection and planning engineers is the development and validation of accurate wind turbine generator(WTG)models to study the impact of increasing wind integration on system protection.Thispaper is on the experimental validation of a generic electromagnetic transient-type(EMT-type)model of aggregated WTGs or wind parks suitable for transient studies.The phasor domain equivalent of the generic model,suitable for protection tools based on steady-state solvers,is also considered.The model has been validated using two sets of actual relay records for the fault response of two wind parks consisting of Type-III WTGs and connected to115 kV and 230 kV transmission systems.The objective is to show that the generic model can reproduce the actual fault response in simulations,and protection engineers can obtain accurate models of wind parks using fault records.A distinctive characteristic of a WTG is its substantially different negative sequence fault current contribution compared to a synchronous generator.The paper shows that the generic model provides enough options to reproduce the negative sequence behavior and hence is suitable for fault studies involving negative sequence-based protection.展开更多
Battery energy storage systems(BESSs)need to comply with grid code and fault ride through(FRT)requirements during disturbances whether they are in charging or discharging mode.Previous literature has shown that consta...Battery energy storage systems(BESSs)need to comply with grid code and fault ride through(FRT)requirements during disturbances whether they are in charging or discharging mode.Previous literature has shown that constant charging current control of BESSs in charging mode can prevent BESSs from complying with emerging grid codes such as the German grid code under stringent unbalanced fault conditions.To address this challenge,this paper proposes a new FRTactivated dual control strategy that consists of switching from constant battery current control to constant DC-link voltage control through a positive droop structure.The results show that the strategy ensures proper DC-link voltage and current management as well as adequate control of the positive-and negative-sequence active and reactive currents according to the grid code priority.It is also shown that the proposed FRT control strategy is tolerant to initial operating conditions of BESS plant,grid code requirements,and fault severity.展开更多
基金supported by the Hong Kong Research Grant Council for the Research Project(No.15229421)the PolyU Presidential PhD Fellowship Scheme。
文摘Integration of inverter-based resources(IBRs)reshapes conventional power swing patterns,challenging the operation of legacy power swing protec-tion schemes.This paper highlights the significant con-sequences of the distinctive power swing patterns exhib-ited by grid-forming IBRs(GFM-IBRs).The swing mechanism involving GFM-IBRs is elucidated using an-alytical modeling of GFM-IBRs with various power syn-chronization loops(PSLs).With varying GFM-IBR pen-etration levels and different generator scenarios,the per-formance of power swing protection functions is examined,including power swing blocking(PSB)and out-of-step tripping(OST).Additionally,the IEEE PSRC D29 test system is employed to present power swing protection results in a large-scale power system integrated with synchronous generators(SGs)and IBRs.The results in-dicate that,GFM-IBRs with sufficient voltage support capability can provide positive impact on power swing dynamics,and power swing protection performance can be enhanced by emulating the inertia and droop mecha-nism of SGs and rapidly adjusting the active power output.However,with high penetration levels of GFM-IBRs,OST maloperation may occur in scenarios with inadequate voltage support capability.
文摘A challenge faced by protection and planning engineers is the development and validation of accurate wind turbine generator(WTG)models to study the impact of increasing wind integration on system protection.Thispaper is on the experimental validation of a generic electromagnetic transient-type(EMT-type)model of aggregated WTGs or wind parks suitable for transient studies.The phasor domain equivalent of the generic model,suitable for protection tools based on steady-state solvers,is also considered.The model has been validated using two sets of actual relay records for the fault response of two wind parks consisting of Type-III WTGs and connected to115 kV and 230 kV transmission systems.The objective is to show that the generic model can reproduce the actual fault response in simulations,and protection engineers can obtain accurate models of wind parks using fault records.A distinctive characteristic of a WTG is its substantially different negative sequence fault current contribution compared to a synchronous generator.The paper shows that the generic model provides enough options to reproduce the negative sequence behavior and hence is suitable for fault studies involving negative sequence-based protection.
文摘Battery energy storage systems(BESSs)need to comply with grid code and fault ride through(FRT)requirements during disturbances whether they are in charging or discharging mode.Previous literature has shown that constant charging current control of BESSs in charging mode can prevent BESSs from complying with emerging grid codes such as the German grid code under stringent unbalanced fault conditions.To address this challenge,this paper proposes a new FRTactivated dual control strategy that consists of switching from constant battery current control to constant DC-link voltage control through a positive droop structure.The results show that the strategy ensures proper DC-link voltage and current management as well as adequate control of the positive-and negative-sequence active and reactive currents according to the grid code priority.It is also shown that the proposed FRT control strategy is tolerant to initial operating conditions of BESS plant,grid code requirements,and fault severity.
