Impact Of Energy Storage And Wind Power Synergistic Dispatching On The Wind Power Integration And CO₂Emission Of Power Grid

Renewable generation including wind power is developing rapidly with energy crisis and climatic deterioration. In traditional power system, generation side is relatively stable and controllable while power load is fluctuant, the intermittency of renewable energy makes generation side to be uncontrollable too. The use of large scale renewable energy need to realize the balance between stochastic power supply and fluctuating demand, therefore, power grid will confront new challenges. Wind power integration into grid is an effective way to realize large-scale wind energy developing and utilizing, and peak regulation capability is the main restrict, conventional units should reduce or increase the output to achieve active power balance. The goal of studying wind power integration into grid is maximizing wind power integration under the condition of power supply and demand balance.The correlation between wind power capacity factor and power load is calculated firstly to study the influence of wind power integration on peak regulation capability of grid, then how to improve peak regulation capability. In this paper, in regard to wind power and energy storage synergistic dispatching, two aspects are considered:concentrating energy storage pumped storage and decentralized plugged-in electric vehicle (PEV), the impact of wind power-energy storage synergistic dispatching on the wind power utilization and CO2emissions of grid are also studied deeply, which is of higher theoretical value and great realistic significance nowadays. Following researches are made to solve the issues mentioned above:1) The impact of wind power integration into grid on peak regulation capability. Through analyzing Shandong power grid, results of calculating correlation coefficient of wind power capacity factor and power load demonstrate that wind power integration into grid has an adverse affect on peak regulation, especially in winter. Peak-valley ratio of equivalent power load is not only related to correlation coefficient but also the average value of wind power capacity factor, and the increment of percentage in spring is the largest, wind power integration into grid puts pressure on peak regulation capability. Wind power increases during valley load period at night, the output of thermal power has been at a low level, surplus wind power can not integrate into grid when thermal power reach the lower limit, Consequently, the constraint of thermal power lower limit is the main factor of restricting wind power integration into grid.2) The impact of pumped storage and wind power (PS-wind) synergistic dispatching on wind power integration and CO2emission of power grid. The mathematical model of PS-wind synergistic dispatching is set up and the utilization and proportion of wind power are calculated to analyze the impact of PS-wind synergistic dispatching and pumped storage’s capacity on wind power acceptance, why the utilization of pumped storage power station decreases with pumped storage capacity increasing is also analyzed. wind power acceptance has to do with season, and pumped storage can play a more important role in grid with higher wind power penetration, consequently, synergistic dispatch is an effective means to realize the integration of large-scale wind power. CO2emission factor of thermal power and CO2emission reductions per year are calculated to study the impact of PS-wind synergistic dispatching on CO2emission.3) The impact of PEV-wind synergistic dispatching on power grid. The mathematical model of PEV-wind synergistic dispatching is set up, the impacts of charging strategy on power grid are analyzed, which shows that PEV-wind synergistic dispatching is effective in improving wind power acceptance and increasing CO2emission reductions. The impact on grid has to do with season, number of PEV and wind power capacity, synergistic dispatch is an effective means to realize the integration of large-scale wind power and PEV. Extra wind power integration into grid is considered as PEV contribution so that CO2emission per kWh under PEV-wind synergistic dispatching is lower than charging freely. Finally, CO2emission reductions of PEV per100km and per year compared with traditional vehicles are caculated to study the CO2emission reduction in transport field.