Study On Scenarios Of Cascading Faults And Control Measures With Large-scale Renewable Energy Incorporated Into Grid

With the continuous construction of 10-gigawatt wind farm bases and 1000-MW photovoltaic power generation bases,the proportion of renewable energy has been increasing,and several cascading failures containing large-scale renewable energy occurred in China and abroad recent years.However,t he research on this problem nowadays only focuses on the straight description of the accident and is absent in analysis of occurrence mechanism.Therefore,it is of great importance to analyze the occurrence mechanism of cascading failure in the constructi on of possible cascading failure scenarios with integration of large-scale renewable energy.This paper first discusses the renewable energy power generation model s including doubly fed wind turbine and photovoltaic power generation system.Based on the PSD-BPA simulation tool,IEEE39 system containing large-scale renewable energy is established to explore the relationship of renewable energy permeability,frequency stability,voltage stability and angle stability respectively by changing the renewable energy permeability in IEEE 39 system.The simulation results illustrated that the stability of the system is getting poor and the stability margin decrease s with the renewable energy permeability increasing.The power system incorporating large-scale renewable energy is then divided into local consumption system and power transmission system according to consumption pattern of renewable energy.Based on the analysis of the causes of the cascading failure in the large-scale renewable energy system and the related theoretical knowledge,the occurrence mechanism of cascading failure s in two system is analyzed qualitatively.Inspired by this work mentioned above,the possible cascading failure scenario in each system is constructed through a lot of simulation.By means of exploring the cascading failure scenarios,three new characteristics of mechanism leading to cascading failures under the integration of large-scale renewable energy are presented:Finally,with the comprehensive consideration of mechanism of casca ding failures,fault ride-through capability renewable energy units and relevant technical regulations,methods,improving wind turbine setting value of high voltage protection and high frequency protection or increasing time delay,are presented to prevent the occurrence of large-range wind turbine tripping and cascading failure.The actual power system simulation validated the effectiveness of proposed measures.