Effects analysis of distributed generation to receiving-end power grid

Grid connection of distributed generation would have a certain impact on safe and stable operation of receiving-end network, so systematic analysis on it would be significant. The method for comprehensive assessment on effects caused by grid connection of distributed generation on power grid is presented. The assessment system is divided into steady-state operation assessment, reliability assessment, and power quality assessment. Steady-state operation assessment is consisted of reactive power demand analysis, delivery capacity analysis, and voltage level analysis. The effects of grid connection of wind farm, different schemes comparison, penetration power, and average wind speed to grid reliability are analyzed. Voltage deviation, voltage fluctuation flicker, harmonic, and three-phase voltage imbalance indexes are used to evaluate the effect to power quality. Specific indexes values are used to measure extent of impact are given and relevant assessment software is developed. Impacts of distributed wind power on Qingdao power grid is analyzed, by taking grid connection of Qingdao Jimo Wind Farm as an example, from the aspects of stable operation, reliability and power quality, etc. and its extent of impact is assessed in a quantitative way, therefore it has guiding significance on power grid planning and operation.