Research On Analysis And Control Of Huolinhe Isolated Power System Frequency Stability With Wind Farms

With the integration of large-scale wind power, due to the small number and capacity of its units and the bad stability of isolated power system, the power fluctuation causes the imbalance of power system resulting in the larger of frequency deviation, which impacts the security and stability of power system and limits the development of local wind energy substantially. Aiming at Huolinhe green economic region power company’s isolated grid, this paper conducts a study on power system frequency stability analysis and control technology.First, the paper describes the theory basis and solution of large-scale wind power fluctuation model based on frequency domain. With the example of Huolinhe isolated power system, the characteristics of wind power fluctuation are studied in both time and frequency domain.Secondly, this paper builds the assessment method of system frequency stability affected by the stochastic fluctuation of wind power, and maximum wind energy penetration limited by grid frequency stability is calculated. Based on the power spectral density (PSD) theory, the assessment model takes wind power fluctuation as a stochastic process and is independent on commercial software, which is the key of the method. The frequency stability of power system can be analyzed quickly and comprehensively.Finally, on the basis of the advanced experience and technology of system frequency stability control at home and abroad, this paper proposes a series of frequency control strategies to suppress frequency variations and improve wind energy integration level in Huolinhe isolated grid, such as the optimal planning of energy storage system, demand response to frequency deviation and multi-windfarms coordination control strategy. The frequency control technology solution and simulation model are put forward. The simulation results verify the effectiveness and feasibility of the control strategies.Derived from the research project "Study on the local power network in the Huolinhe green economic region to enhance its capability to accept wind power" funded by the CPI Mengdong Energy Group Co., Ltd, this paper has proposed a series of control strategies to impove the wind power integration level limited by system frequency stability, which are useful to the realization of local consumption of of large-scale wind power and clean production of high energy-consuming industries. This research has certain reference for the construction and application of the actual isolated power system project.