| With the rapid socio-economic development and people’s living standardsimprovement, global energy is draining. Worldwide energy shortage and environmentalpollution has become one of the key issues restricting the sustainable development ofhuman development. As one of the major institutions of primary energy consumption,power system is obligated to developing new energy generation and protecting theenvironment. Compared with other clean energy sources, wind energy resources areabundant and widely distributed around the world, and it has great potential fordevelopment. However, the wind power output is stochastic and difficult to predictive. Iflarge-scale wind power is connected to the grid, the production and operation of thepower system will be changed profoundly. It adds to the difficulty of scheduling thepower system.Battery energy storage possesses the technical advantages of flexible operationmode and rechargeable running characteristics. It has become an effective means toimprove the wind power output characteristics and solve the problem of unbalanced ofwind power output.Combining with the current wind power forecast level, the wind-battery energystorage combined system optimization operation is studied through the analysis of windpower output characteristics and battery energy storage properties.Firstly, according to the output model of the wind based on the scenario probabilitytheory and the model of battery energy storage system, wind-battery energy storagecombined optimal operation model is proposed. The model was divided into two stages.The first stage is the plan output stages. In this stages, combining with the price, batteryenergy storage translate the wind power output on the time axis within the scope of thetechnical constraints. The wind power output in low price period is transferred to peakelectricity price time to sell, a higher sell electricity efficiency is obtained through thisway. In the second stages, namely the adjustment phase of deviation, with the flexibleadjusting performance, battery energy storage adjusts the wind power output deviationson each scene, reducing the punishment caused by the amount of unbalance. With combining the earnings on the previous the cost on the former phase, a model of optimaleconomic benefit of wind–battery combined system is established.Secondly, the charge and discharge strategy of battery energy storage is researched.In this model, two stages function of battery energy storage is coordinated. With makingthe optimal use space of power and capacity, the charge and discharge of battery energystorage strategy is proposed.In addition, capacity optimization model of battery energy storage is established.With a target of optimization the annual net economic benefit, a method of optimizingbattery energy storage capacity is put forward.Finally, the models and methods mentioned in this paper are simulated andcalculated with application of actual data, the results are analyzed. Numerical exampleresults show the validity of the model in this paper, at the same time it also play a guidingrole in the work of large-scale wind power interconnecting to power system. |
