Frequency Control Operation of ESSto Improve the Power System Reliability

Abstract

Background/Objectives: The Battery Energy Storage System(BESS) has been maintained power voltage value to rapidly response speed for steady state in the power system. It is operating the BESS to securing the reactive power.

Methods/Statistical analysis: It has been investigated the output control result of large capacity ESS due to the failure of the nuclear power generators. The power system would be operated to maintain the voltage level by Governor Free Control(GFC) and Automation Generation Control(AGC). The BESS is evaluated to compare the real power system with simulation power system in fault state. The BESS has been rapidly responded speed in steady state, and recovered frequency in transient state. The control methods are classified the steady state, transient state, and change from normal to transient state operation.

Findings: The steady state output was proportional to frequency error and system constant. The transient state was operated when the rate of charge of frequency was less than -0.0306[Hz/s], and the system would be fully discharged. It was stopped the operation when the frequency would be recovered to 59.9[Hz] within the system error of ± 0.01[Hz]. Recovery from transient state to steady state has been restored to linear slop for 0~10[s] until transient discharge power.

Improvements/Applications: It should be used for expended application of the BESS in the power system as stable power supply. It would be expected that the reliability of the power system by fast response speed for spinning reserve power.

Keywords: Battery Energy Storage System(BESS), Transient State, Nuclear Power Generator, frequency, Reserve Power, reliability.