Optimization method for improving safety and stability of grid frequency

Abstract

The invention discloses an optimization method for improving safety and stability of grid frequency. The optimization method comprises the following steps of: determining a grid size, grid characteristics, an operation mode and a setting condition of a safety and stability control device of a target power system; determining whether the risk that the grid frequency is out of limit exists after a grid fails; implementing a measure for cutting off a pumped storage power station unit; determining a control measure for power of a speed-up or speed-down direct current line; and selecting starting frequency of the power of the speed-up or speed-down direct current line and determining speed-up or speed-down regulating quantity for power of the direct current line through simulating calculation. According to the optimization method, the frequency stability of the grid after failure is improved by using the control measure for the direct current line and a pumped storage power station, the direct current adjustable capacity and the pumped storage power station in the system can be effectively utilized, the frequency maintenance level of the system after failure is improved, the safety and stability control measures such as cut-off of a power set and load shedding are reduced, and the influence of the failure of the power system on power operation, industrial production and life of people is reduced.

Description

technical field [0001] The invention belongs to the field of power systems, and in particular relates to an optimization method for improving the safety and stability of power grid frequency by using a direct current line and a pumped storage power station. Background technique [0002] One of the important symbols of the stable operation of the power system is the stability of the system frequency. Frequency stability refers to the ability of the system frequency to maintain or recover within the allowable range without frequency collapse after active power disturbances occur in the power system. If the frequency instability occurs in the system, it will lead to a large-scale power outage with serious consequences. With the development of power system power generation and transmission technology, the maximum capacity of a single unit has reached 1 million kilowatts, the transmission capacity of a single UHV AC line has reached 5 million kilowatts, and the transmission capa...

AI Technical Summary

Problems solved by technology

The measure of increasing the spinning reserve capacity of the unit can use the frequency regulation function of the unit to increase the output of the unit to improve the stability of the grid frequency when the grid frequency drops after a fault, but it will cause the unit to be unable to run at full capacity for a long time during normal operation and reduce the power generation efficiency of the power plant; The measure of configuring the high-cycle cut-off protection device can automatically cut off the unit when the grid frequency rises to a certain level, but cutting off the unit will reduce the total moment of inertia of the system and the voltage support capacity of the local area, which is detrimental to the stability of the system; configuration Low-frequency load shedding device measures belong to the category of the third line of defense of the power system, and are the most basic and important protection measures for the power system. The collapse of the system is avoided, but the power outage caused by the loss of a large number of loads will have a great impact on social production and residents' lives

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