Research On Power Grid Load Frequency Control System With Pumped Storage Power Station

With the enlargement of the power grid scale, power grid operating environment is also showing a complex trend, the security of the power grid daily operation and the stability problem after disturbance is getting more and more attention by the people. The construction of strong smart grid and the advance of special high-voltage network lead to outside electric power of the grid increasing. The character of large receiving end grid becomes more obvious, reinforced the emergency handling capabilities facing sudden large-scale power loss is imminent.Pumped storage power station is a mature energy storage technology which has been applicated in electric network, the use of pumped storage power stations has played a great role of power grid daily operation. With the enlargement of power grid scale and operation environment is more complex, the pumped storage power station has the ability to assume more responsibility except the original role, so the operation mode of pumped storage power station needs further study.This paper is based on the pumped storage power station, load frequency control in their daily operation of the power system and the power support under the state of emergency were studied, and the main work is as follows:(1) Summarize common elements of the traditional load frequency control system model; establish the transfer function and state space model of a single area load frequency control. Analyze the defects of the traditional linear model and establish a LFC model of two region reheat thermal considering nonlinear the nonlinear based on the analysis of the nonlinear part of power system.(2) Analyze the work model of pumped storage power station, divided into power generation and pumping conditions. Model of pumped storage power station were established corresponding to different operating conditions. Combining the pumped storage power station and regional load frequency control model proposed area load frequency control model with pumped storage power station. According to this model, design the corresponding controller for different units, the simulation shows the frequency change is reducing, the restore speed is faster and the dynamic characteristics is getting better while pumped storage power station is added in the power grid load frequency control system.(3) Aiming at the deficiencies of current power system emergency DC power support system, construct the pumped storage power station emergency power support system based on the ladder pumped storage power station model. Formulate the implementation process of the pumped storage power stations emergency power support system by designing the start condition, power allocation process and exit process of the support system. Through the united test of multi station verified the correctness of logical of the whole system; laid a foundation for practical application of the pumped storage power station emergency power support system.