| In recent years, with the energy problem and environment problem is increasinglyserious, new energy has been received strong support from governments, PV (photovoltaic)grid-connected power system is increasing day up. However, PV power generation systemand power grid operation of the generator will make the whole system structure andoperation mode changed. Therefore, how to guarantee the safe and reliable operation ofpower system will be the important content in the research of photovoltaic powergeneration technology, islanding detection of grid-connected photovoltaic system is arequired function.When the network part of the line due to a breakdown or repair power failure, powerfailure circuit by connecting to power grid system, and together with the surrounding loadconstitute a self-contained power supply Island, photovoltaic power generation system inisland operation state can have very serious consequences, such as the load end userequipment damage; Island Line endanger the personal safety of maintenance personnel; inre closing before did not eliminate isolated island effect will result in not synchronous gridand other.The PV grid-connected system islanding detection research，the following work hasbeen done by this paper,First, the islanding detection research background is elaborated and the significance,introduced the islanding detection history and research status of domestic network, theislanding phenomenon causes and harm is detailed analysised, domestic and internationalgeneral islanding detection standard is introduced, the common passive and activeislanding detection method is introduced, by comparing their respective advantages anddisadvantages are pointed out their applicable scope.Second, In Hunan Province Department of education on the project of " solarphotovoltaic power supply system based on micro mixing (10A114)", hall of Hunanprovince science and technology project" solar photovoltaic micro power DC powersupply system research and development (2010FJ3116)" as well as the third Hunanprovince college students study and innovative experiment project of" solar photovoltaicgrid-connected system in island monitoring" support, a new electric current perturbationmethod for islanding detection is put forward by this paper, the methods for the detectionof principle is expounded, and through Matlab/Simulink and3kW photovoltaic invertersimulation research and experiment, the simulation and experimental results verify thefeasibility of the method, the testing time is short, and has a certain application value. Third,300kW and500kW grid-connected photovoltaic power generation system isused the research, the new current-disturbed islanding detection method for furtherhigh-power grid-connected system simulation; simulation results further validate thefeasibility of this method.Fourth, the optimal control islanding detection method, make up the active currentdisturbing islanding detection method, and through Matlab/Simulink were simulated, thesimulation results verify the feasibility of the method, the detection time is shorter, theinductive load and power balance can also detect islanding occurrence.Finally,300kW and500kW grid-connected photovoltaic power generation system isused to research, the optimal control islanding detection method for further high-powergrid-connected system simulation, simulation results further validate the feasibility of thismethod, has a certain application value.. |
PDF Full Text Request