Research On Coordinated Control Between Wind Power System And Energy Storage Devices

Wind, solar and other green energy power generation is of great significance to achieving a low-carbon economy, energy saving and environmental protection. However, affected by natural conditions and other factors, wind energy has the characteristics of strong randomness, intermittent and volatility, causing irregular wind power generation system output power fluctuations. The large-scale integration of wind power can put the operation of power system into risk and affect the power quality. Therefore, the study of how to smooth the fluctuant output of wind power has a significant advantage for large-scale development of wind power.In this paper coordinated control between wind power system and energy storage devices is researched. Different types of storage devices are applied to smoothing wind power, and using fuzzy control to achieve the internal coordinated control of energy storage system and to accomplish optimal power allocation internal compensation, taking into account coordination and control between wind power system and energy storage system. Thereby a good stabilize wind power can be achieved under the premise that combined system safe and stable operation. Details are as follows:1. This paper analyzes the operating principle of Doubly Fed Induction Generator (DFIG). A mathematical model of the wind power generation system is set up. The control strategy of Maximum Power Point Tracking (MPPT) is researched, as well as effects of wind randomness on wind power using simulated wind model. Theoretical analysis of effects of wind power fluctuations on power grid especially on the grid voltage is given.2. A control strategy for smoothing wind power fluctuation based on hybrid energy storage system consisting of power type and energy type storage device is presented. In consideration of the importance of choosing a reasonable smoothing goal, this paper proposes a running average algorithm to determine the desired output of wind power, then control strategies of battery and ultra-capacitors are designed respectively. Making the fluctuation and smoothness of wind power which has been compensated by energy storage system improve greatly.3. Put forward a method to adjust the filter time constant considering the state of charge of battery so as to achieve the internal coordinated control of energy storage system. Making use of Mamdani fuzzy controller changes time constant of low pass filter. As a result of filters delayed effects, Takagi-Sugeno fuzzy controller is used for adjusting the battery compensated reference power value. The control strategy can optimize power distribution between different type of storage device, ensure the safe use of battery, extend its lifespan.4. A coordinated control strategy between wind power generation system and energy storage system. The control strategy establishes an analytical, judgment, coordination mechanisms. Through collecting storage system status variables, coordinated controller determines energy storage system access or removal operation, as well as pith angel system start or stop. The proposed coordinated control strategy on the premise of smoothing wind power fluctuations greatly also can ensure the stability and security of wind power system and energy storage system respectively.