Frequency Spatial Distribution Mechanism of Power Grid Based on Complex Frequency

doi:10.16183/j.cnki.jsjtu.2024.333

Abstract

Abstract:

Frequency deviations emerge at different nodes after a power grid disturbance, which is defined as the spatial distribution of system frequency. Previous studies have proposed a frequency divider formula to estimate this frequency distribution. However, the assumptions and simplifications adopted in its derivation introduce considerable errors. To address this issue, this paper proposes an accurate formula for estimating frequency distribution based on the concept of complex frequency, considering the variations in the magnitude and phase angle of voltage vectors. The proposed formula allows the spatial distribution mechanism of grid frequency to be analytically described, revealing the inherent law of frequency distribution and proving that the frequency distribution level is correlated with the impedance distribution and voltage level of the network. Compared with the existing frequency divider formula, the proposed formula more reasonably accounts for factors such as network resistance, loads, and the magnitudes and angles of node voltages and generator internal potentials. Its rigorous derivation leads to higher accuracy. Time-domain simulation results in the IEEE 39-bus system and 145-bus system verify the accuracy of the proposed formula.

Key words: complex frequency, frequency distribution, frequency divider, frequency dynamics

CLC Number:

TM743

LIU Xin, MA Qingyuan, CHEN Lei, ZHANG Yagang, XU Haichao, JIANG Guoqi, CHEN Li. Frequency Spatial Distribution Mechanism of Power Grid Based on Complex Frequency[J]. Journal of Shanghai Jiao Tong University, 2026, 60(6): 925-931.

Figures/Tables 6

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