采用滑模频率偏移(slide-mode frequency shift,SMS)法、Sandia频率偏移(sandiafrequency shift,SFS)法检测孤岛时,并网逆变器存在相位检测延时,会对孤岛检测盲区的精度产生一定的影响。为克服这一问题,在前期工作的基础上改变下垂锁相...采用滑模频率偏移(slide-mode frequency shift,SMS)法、Sandia频率偏移(sandiafrequency shift,SFS)法检测孤岛时,并网逆变器存在相位检测延时,会对孤岛检测盲区的精度产生一定的影响。为克服这一问题,在前期工作的基础上改变下垂锁相环的扰动参数,进而提出改进的频率偏移孤岛检测方法(islanding detection method,IDM)。推导了3种孤岛检测方法在电网频率突变、电网频率偏离额定值2种情况下逆变器并网基准电流的表达式,分析了各自的谐波含量,在具有相同孤岛检测盲区的情况下所提IDM性能最优。仿真结果验证了理论分析的正确性。展开更多
孤岛检测的方法很多,尤其是主动式孤岛检测方法。如何在众多的主动孤岛检测法中选择最合适的方法是应用中的难点。针对主动法中的应用较多的滑模频率偏移法和有源频率偏移法,分别对其检测盲区、检测速度、对电能质量影响进行机理分析。...孤岛检测的方法很多,尤其是主动式孤岛检测方法。如何在众多的主动孤岛检测法中选择最合适的方法是应用中的难点。针对主动法中的应用较多的滑模频率偏移法和有源频率偏移法,分别对其检测盲区、检测速度、对电能质量影响进行机理分析。理论分析结果表明在盲区相同时,SMS(Slip-Mode Frequency Shift)法造成的逆变电流总谐波含量更小,但SMS法的检测速度在不同参数条件下存在较大区别。在Matlab/Simulink中对孤岛检测方法进行建模,实验结果证明了理论分析的正确性。展开更多
Responding to the problem of increased load demand, progress has been made to develop a new smarter infrastructure, which employs a decentralised approach. This smart decentralised system, termed smart grid, is compos...Responding to the problem of increased load demand, progress has been made to develop a new smarter infrastructure, which employs a decentralised approach. This smart decentralised system, termed smart grid, is composed of micro grids which utilise a combination of distributed energy resources (DER). The DERs can either be operated in parallel with the grid or in autonomous condition (intentional-islanding). Operating the DER under intentional islanding condition is seen as the next stage in smart grid’s future development which requires intelligent control implementation. In order to utilise this intelligent control, immediate detection of islanding is essential. This paper proposes a new smarter islanding detection method, which implements the forecast capability of smart grid by detecting the fluctuations before islanding occurs. The proposed method has been tested in simulation and compared against the current islanding detection methods. The simulation results have successfully proven the benefits of the new proposed method over the current methodologies in island detection.展开更多
Due to the increased penetration of multi-inverter distributed generation(DG)systems,different DG technologies,inverter control methods,and other inverter functions are challenging the capabilities of islanding detect...Due to the increased penetration of multi-inverter distributed generation(DG)systems,different DG technologies,inverter control methods,and other inverter functions are challenging the capabilities of islanding detection.In addition,multi-inverter networks connecting the distribution system point of common coupling(PCC)create islanding at paralleling inverters,which adds the vulnerability of islanding detection.Furthermore,available islanding detection must overcome more challenges from non-detection zones(NDZs)under reduced power mismatches.Therefore,in this study,a new method called parameter self-adapting active islanding detection was utilized to minimize the dilution effect and reduce NDZs in multi-inverter power systems.The method utilizes an active frequency drift(AFD)method and applies a positive feedback gain of adoption parameters,which significantly minimizes NDZs at parallel inverters.The simulation and experimental outcomes indicate that the proposed method can effectively weaken the dilution effect in multi-inverter networks connecting the distribution system PCC.展开更多
文摘孤岛检测的方法很多,尤其是主动式孤岛检测方法。如何在众多的主动孤岛检测法中选择最合适的方法是应用中的难点。针对主动法中的应用较多的滑模频率偏移法和有源频率偏移法,分别对其检测盲区、检测速度、对电能质量影响进行机理分析。理论分析结果表明在盲区相同时,SMS(Slip-Mode Frequency Shift)法造成的逆变电流总谐波含量更小,但SMS法的检测速度在不同参数条件下存在较大区别。在Matlab/Simulink中对孤岛检测方法进行建模,实验结果证明了理论分析的正确性。
文摘Responding to the problem of increased load demand, progress has been made to develop a new smarter infrastructure, which employs a decentralised approach. This smart decentralised system, termed smart grid, is composed of micro grids which utilise a combination of distributed energy resources (DER). The DERs can either be operated in parallel with the grid or in autonomous condition (intentional-islanding). Operating the DER under intentional islanding condition is seen as the next stage in smart grid’s future development which requires intelligent control implementation. In order to utilise this intelligent control, immediate detection of islanding is essential. This paper proposes a new smarter islanding detection method, which implements the forecast capability of smart grid by detecting the fluctuations before islanding occurs. The proposed method has been tested in simulation and compared against the current islanding detection methods. The simulation results have successfully proven the benefits of the new proposed method over the current methodologies in island detection.
基金supported by the National Natural Science Foundation of China under Grant No.61671109.
文摘Due to the increased penetration of multi-inverter distributed generation(DG)systems,different DG technologies,inverter control methods,and other inverter functions are challenging the capabilities of islanding detection.In addition,multi-inverter networks connecting the distribution system point of common coupling(PCC)create islanding at paralleling inverters,which adds the vulnerability of islanding detection.Furthermore,available islanding detection must overcome more challenges from non-detection zones(NDZs)under reduced power mismatches.Therefore,in this study,a new method called parameter self-adapting active islanding detection was utilized to minimize the dilution effect and reduce NDZs in multi-inverter power systems.The method utilizes an active frequency drift(AFD)method and applies a positive feedback gain of adoption parameters,which significantly minimizes NDZs at parallel inverters.The simulation and experimental outcomes indicate that the proposed method can effectively weaken the dilution effect in multi-inverter networks connecting the distribution system PCC.
