Abstract
Pumped storage power station is an important regulating tool for peak load regulation and frequency regulation of the power grid, especially its primary frequency regulation function, which is of profound significance for the safety and stability of the power grid. As the core equipment of the pumped storage power station, the reversible design of the pump turbine makes it easy to have hydraulic fluctuation and mechanical instability when the unit runs to the “S” characteristic area, which will cause the frequency oscillation of the generator under the condition of primary frequency regulation. Therefore, some innovative work is studied in this paper: (1) an accurate hydraulic-mechanical-electrical coupling system mathematical model of pumped storage unit regulation system (PSURS) is established based on full characteristic curve of the pump turbine and seventh-order synchronous generator and excitation system; (2) the dynamic response characteristics of primary frequency regulation of pumped storage unit (PSU) under different water heads and different frequency disturbances are analyzed by numerical simulation; (3) in view of the unstable condition of the unit under the large frequency disturbance when it operates in the low head and small load area, the objective optimization function considering the ITAE index of hydraulic, mechanical, and electrical factors is proposed; and (4) fractional-order PID controller and the bacterial-foraging chemotaxis gravitational search algorithm (BCGSA) combined optimization strategy is used for PSURS optimization regulation and parameter optimization. The results show that the joint optimization strategy proposed in this paper has smaller objective function value, and makes the PSURS pass through the unbalanced area quickly, with better primary frequency regulation speed and smaller regulation depth.
Highlights
In recent years, with the rapid growth of China’s power load, the demand for the stability of the power grid is rapidly increasing, and the shortage of peak load regulation capacity has become an important problem restricting the development of the power system. erefore, the combined operation of pumped storage technology and new energy is widely used in power system [1, 2]
It can be seen from some accidents in the power system that the units with the input of primary frequency regulation function and the correct setting of primary frequency regulation parameters can greatly restrain the expansion of the accident and ensure the stability of the power system [9,10,11]. e pumped storage unit regulation system (PSURS) has strong nonlinear and time-varying characteristics [12], and PSU has “S” characteristic area, which leads to the frequency oscillation of the unit under low water head [13, 14]. erefore, it is of profound significance to optimize the dynamic performance and control quality of PSURS under the condition of low water head [15]
When the unit participates in primary frequency regulation [18], the frequency disturbance will greatly increase the probability of wide range fluctuation of the PSU’s frequency. e traditional PID controller cannot adjust the frequency fluctuation of PSU well
Summary
With the rapid growth of China’s power load, the demand for the stability of the power grid is rapidly increasing, and the shortage of peak load regulation capacity has become an important problem restricting the development of the power system. erefore, the combined operation of pumped storage technology and new energy is widely used in power system [1, 2]. E pumped storage unit regulation system (PSURS) has strong nonlinear and time-varying characteristics [12], and PSU has “S” characteristic area, which leads to the frequency oscillation of the unit under low water head [13, 14]. Xu et al designed an adaptive fast fuzzy fractional-order PID controller to improve the dynamic performance of pumped storage units under low water head no-load condition [21]. Erefore, this paper puts forward an accurate hydraulic-mechanical-electrical fine coupling system mathematical model of PSURS based on and high-order synchronous generator and full characteristic curve of pump turbine.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
