Research On A New Power Distribution System In Phase Change Energy Storage Of Wind Farm

With the continuous development of the wind farm, its negative impact on the gridmuch more remarkable. The impact of the large-scale grid-connected wind farms onsystem stability, power quality and generation dispatch cannot be ignored. If theseproblems cannot be treated properly, not only will the electricity load side face danger,but also the whole power grid maybe collapse. These problems seriously hindered thedevelopment and the use of wind power. Configuring a certain capacity of the energystorage system has been evident that it is an effective way to achieve smooth control ofactive power. With the consideration of the characteristics of different energy storage,power distribution system must be set to control the power.A new power distribution system based on phase change energy storage of windfarm is proposed to replace traditional charging and discharging controller. Ahierarchical power control and regulation systems used a new type of power adjustingtransformer and the electric heaters groups is proposed. The new system is proposed toreplace traditional charging and discharging controller. When the wind turbine poweroutput exceeds the threshold, the system can realize the smooth power output of windfarms and conduct the excess power to energy storage. The system possesses twoadvantage: real-time power regulation and storage capacity variation, and can keep thewind turbines operating under the mode of maximum power point tracking strategy,which effectively reduces the waste of wind energy.The system mainly consists of power monitor, adjust power transformers, electricheater groups and control unit. A new type of power adjusting transformer is proposed,the requirements and mathematical model of power adjusting transformer is described.Phase change energy storage technologies and the electric heaters groups of hierarchicalcontrol is also introduced, meanwhile, the connection and function of each componentare elaborated.The principle of power distribution system is introduced: considering thecooperation operation of adjustable power transformer and the electric heater group, thetime delay of power distribution system, the operation mode of power distributionsystem is designed, corresponding formulae and control strategy are presented. Then theconfiguration of the system is discussed in the paper, the method to determine the mostvalue of the power adjusting transformer ratio is also given. After that, the method of calculating the mathematical expectation of wind farm output power is analyzed fordetermination of maximum power, the system initial value selection considering thesystem running and economy index is discussed.The case study is carried out on the system by PSCAD/EMTDC. The simulationresults confirm that the power real-time control system of wind farms has goodpracticability.