Method for controlling participation of battery energy storage system in power grid secondary frequency modulation

Abstract

The invention provides a method for controlling participation of a battery energy storage system in power grid secondary frequency modulation. An adjustment coefficient of participation of the battery energy storage system in the power grid secondary frequency modulation and a relation between the adjustment coefficient K2 and the amount of unbalance [delta]P of a load and generated power in a power grid are determined through the amount of unbalance [delta]P of the load and generated power in the power grid, after the amount of unbalance [delta]P of the load and generated power in the power grid goes through a generator-load frequency characteristic link, a frequency difference value [delta]f of a system is obtained, after a PI link of each power supply participating in the power grid secondary frequency modulation, to-be-changed-power of each power supply is obtained. The method can change the final output magnitude of participation of the battery energy storage system in the power grid secondary frequency modulation, the battery energy storage system realizes participation in the power grid secondary frequency modulation process through charging and discharging control, fire coal loss of a traditional unit can be reduced, and thus frequency modulation cost is reduced; and a balance between power supply power generation and load power utilization can be maintained rapidly.

Description

technical field [0001] The invention relates to a control method for a battery energy storage system participating in secondary frequency regulation of a power grid. Background technique [0002] Power system frequency is one of the three major indicators of power quality, and its deviation reflects the balance between the active power provided by the system and the load demand. Since the primary frequency regulation of the power grid relies on its own inherent frequency characteristics to prevent system frequency deviation, and cannot achieve zero-difference regulation, the secondary frequency regulation is to change the position of the differential regulation characteristic curve of the generator set on the basis of primary frequency regulation to achieve zero-difference regulation. Suitable for adjusting load fluctuations in minutes or worse. [0003] The increasing shortage of traditional energy sources and the deterioration of the environment have promoted the rapid de...

AI Technical Summary

Problems solved by technology

However, due to the inherent characteristics of traditional frequency modulation units, especially in power systems containing large-scale new energy power generation, there are various defects and deficiencies in traditional frequency modulation methods

Hydroelectric units are the most suitable energy source for participating in power grid frequency regulation, but hydroelectric units are easily affected by regions and seasonality

Traditional frequency modulation units are composed of mechanical devices with rotational inertia. It takes a relatively long period of time to convert primary energy into electrical energy and then reach a certain output power according to frequency modulation instructions. The response is slow and creeping The slope rate is low, coupled with the inertia of the unit, it is not easy to change the direction when participating in frequency regulation, and it is easy to cause delays and deviations in frequency regulation. Moreover, the traditional unit participates in grid frequency regulation and changes the adjustment direction frequently, which not only aggravates the wear and tear of the equipment, and increased fuel usage and operating costs

Images