The Research And Implementation Of Islanding Detecting Of Large-scale PV Plants Based On GOOSE

As a kind of renewable green energy,Solar power has become an irreplaceable part of the power system.In recent years,our country is stepping up efforts to promote the development of PV station station,and introduced the related policies to encourage PV station grid operation.PV grid-connected operation will bring to power a range of effects.PV station plant operating experience at home and abroad show that large on-grid PV station station there are technical problems and safety concerns: The control difficulties of the grid voltage and frequency due to PV stochastic volatility;The contradiction between island detection of PV station station and low voltage ride through;The power reaches a certain level,Harmonic,asymmetrical,flicker,shocks and other power quality issues affecting the PV.In this paper Islanding detection methods for large PV plants are studied.Based on 20 MWp photovoltaic power plant as an example,Analysis of structure of large on-grid PV station station on the basis of theoretical analysis and simulation,to study the Islanding detection methods,this paper proposes a remote island type detection method suitable for large scale photovoltaic power station.Traditional remote island detection is a detection method based on relay protection,through the test on power lines cause island system existence state of circuit breaker to judge the island.Non-detection zone of this method is small,but economy is low and dependent on developments in communications technology.When the power system is in stability and connected,the frequency of the PV station and the remote substation are the same;While the PV station disconnected with the grid,the frequency of the PV station generally becomes different from that of the grid.The frequency difference between the PV station and the remote substation can be used as an index to distinguish the both connection status,which is the basic principle to identify islanding condition;GOOSE communications ensuring the timeliness and reliability of information transmission.Simulation and experiments are two effective means to develop the research.In the paper a simple grid-connected PV station model is developed using MATLAB.Simulation and experimental results show that the islands of Islanding detection methods can be used to detect,is feasible.