Study On The Frequency And Voltage Of Coordination Between Generators And Power Grid Of The Wind Power Uniting Thermal Power Outgoing System

With the planning and construction of giant wind power base in our country, there will be more large-scale wind farms connected to the power grid. Wind power will be sent in the form of "wind power uniting thermal power". The operation modes of wind power uniting thermal outgoing system changed in different forms. The grid frequency and voltage affected by many factors in which the relationship are complex. The frequency control strategy of thermal power and the voltage control strategy of SVC of substations and controllable shunt reactors are formulated difficultly. Therefore, it is of significance to research coordination between generators and power grid of "wind power uniting thermal power" outgoing system.The basic structure of control model of the wind turbine and thermal power units are analyzed in this paper. A typical significance wind power uniting thermal power simulation system was established and the control characteristic differences of supercritical unit and subcritical unit are compared. Then the theory of solid-speed wind turbine removed by over-speed protection because of its speed instability is analyzed deeply under short-circuit fault. Taking the region in Gansu Province where the power delivery systems of the local grid include both wind power and thermal power as an example, the primary frequency regulation of the thermal power generating units, the causes of repeated movement of OPC and strategies in the case of interruption between the region and the main grid are analyzed. The power system frequency control strategy of thermal power dealt with mass wind turbine off-grid is proposed to enhance mechanical power emergently. By monitoring the amount of off-grid wind turbines and thermal power spinning reserve capacity, the mechanical power of thermal power units enhanced emergently is calculated. Thus the CCS of thermal units from normal AGC control is switched to emergency power control. The frequency fluctuations is reduced and the stability of the system frequency is improved. The effect of the strategy is verified by simulation. The types and operating principle of FACTS in the Jiuquan wind farms and the first and second channels for power transmission of Xinjiang power grid are analyzed. The effect of FACTS for suppressing voltage fluctuation is studied based on the simulation for wind turbine off-grid. Finally, its put forward suggestions for the effects that the large-scale thermal power generating units planned in the Jiuquan wind power base have better performance on suppression of voltage fluctuation by strengthening the excitation systems.