Large-scale Hybrid Wind-solar Systems Modeling And Voltage Stability Analysis Of Power System

Currently, the global economy is developing rapidly, people increasingly pay attention to the environment and natural resources. Represented by wind energy and solar energy, the clean energy is developing rapidly. And because it has different characteristics from traditional thermal such as intermittent, randomness etc., when it integrated to the grid, the impact to the power system can not be ignored. Worldwidely, the large-scale trip-off of wind power and photovoltaic occurs frequently, which seriously affect the power grid safe and stable operation.Domestic and foreign scholars have studied for the influence of static stability, transient stability, frequency stability and voltage stability, etc. when wind and photovoltaic integrate to power system. However, considering the wind and photovoltaic hybrid power systems affect the grid is not sufficient. In this paper, wind and solar power generation system integration impact on system voltage stability are analyzed.Accuracy and precision mathematical model wind turbine and photovoltaic systems directly affects the analysis of the impact on grid stability after its integration. This article firstly introduces the mathematical model of double-fed wind turbine and photovoltaic arrays. According to the mathematical model of double-fed wind turbine and photovoltaic arrays, it builds simulation models based on PowerFactory 15.1 power system simulation software. In order to effectively improve the transient characteristics of DFIG, in the rotor control of double feed-side it proposes a turbine supplementary damping controller strategy. Finally, the simulation models are tested from static and transient angles and the results show that the simulation model is built correctly and can reflect the actual situation. It verifies the validity of the simulation model.This paper studies the power system voltage stability, including static stability and transient stability. For static voltage stability, it uses the current mainstream PV curve method and VQ curve method, which not only can calculate the voltage stability margin of the system, but also be able to give all kinds of sensitivity indicators may well reflect voltage stability of the power system. And for power system transient stability, it adopts the EEAC analysis method, and takes critical fault clearing time as an indicator of the ability to characterize transient stability. This method can quantitatively analyze different scenery access capacity effect of transient stability.Finally, it sets up wind and solar power generation system and uses the above method to analysis an IEEE 9 bus system and an actual power grid simulation. It analyzes impact of the static and transient stability when the hybrid system connected to the power grid.