Research On The Several Key Issues Of Hybrid Power System Combining Wind Farm With Small Gas Turbine Power Plants

Owing to the randomness, intermittence and uncontrollability of the incoming wind, the output fluctuation of wind farm, un-dispatching and power grid stability gradually became the key and difficult problems with the large-scale development of wind power. It is very important to study how to solve those technological bottlenecks radically. Considering the characteristics of the output fluctuation of wind farm, this dissertation presents the several key issues of hybrid power system combining wind farm with small gas turbine power plants. The main contributions of the paper are as follows:1. The frameworks, principles and design scheme of wind/gas turbine hybrid power system are proposed. Based on the output fluctuation of wind farm and un-dispatching ability, this paper presents the conditions, design principles and plant structures to form the hybrid power system. The result shows that small gas turbine power plants can be used to compensate the output fluctuation of wind farm. According to the local wind energy resource, the design scheme of the wind/gas turbine hybrid power system in Dabancheng (Xinjiang region) wind farm is investigated.2. The economic and sensitivity of the wind/gas turbine hybrid power system are analysized. Applying economic and sensitivity analysis methods on wind/gas turbine hybrid power system, the results show the hybrid power system is economic feasible. The measures for reducing the cost of electricity of hybrid power system are discussed in detail.3. A prediction model of wind speed and an integrated model of wind farm are presented. Using actual wind speed data and AMRA prediction model, a suitable model structure and relative parameters are choosen to predict the wind speed. According to analysis on the characteristics of incoming wind speed and energy distribution of wind turbine, integrated wind-power model of wind farm is proposed on the base with consideration of several effects and assumptions.4. The unit commitment and optimal load sharing model are proposed. The minimum cost of electricity in unit time interval is considered as the objective function. The dispatching load requirement from power grid, partial load efficiency of gas turbine, minimal start/stop number and time interval are used as constraints. Applying genetic algorithm, the unit commitment and optimal load sharing among the gas turbine power plants are solved for actual system.Finally, the simulation models and dynamic characteristics of wind-gas turbine hybrid power system are discussed based on the model of wind turbine unit, power grid and gas turbine power plants. The result shows gas turbine power plants can respond adequately to compensate the output fluctuation of wind farm.