Electric Power ›› 2024, Vol. 57 ›› Issue (2): 82-93.DOI: 10.11930/j.issn.1004-9649.202302050

• Power System • Previous Articles     Next Articles

Reduced-order Modeling and Control Parameter Design of High-Frequency Oscillation in Low-Voltage DC System

Xiao LIU(), Chunfa DONG, Hanbing QU, Guangyuan YU, Shancheng SU   

  1. 1. State Grid Jinan Power Supply Company, Jinan 250012, China
  • Received:2023-02-14 Accepted:2023-05-15 Online:2024-02-23 Published:2024-02-28
  • Supported by:
    This work is supported by Science and Technology Project of State Grid Shandong Electric Power Company (Multi-timescale Stability Mechanism and Optimal Control of DC Distribution System, No.520601220008).

Abstract:

The interaction between voltage-source converters, DC lines and constant power loads (CPLs) leads to high-frequency oscillation instability in low-voltage DC systems. For this reason, a normalized reduced-order model applicable to the analysis of high-frequency oscillations of the system is established in this paper, with the causes of the high-frequency oscillation instability of the system explained from the perspective of the normalized reduced-order model. On the basis, an analysis method of feasible region of control parameters that can inhibit high-frequency oscillations is proposed. This feasible region cannot only present visually the low-frequency stability or high-frequency instability regions of the system under different control parameters, but also show customized design curves of the system-level dynamic characteristics (oscillation frequency and damping factor) in detail in the stability region. Finally, the simulation example of the low-voltage DC system is built via PLECS software, with the validity of the normalized reduced-order model and the feasible region of control parameters verified by multiple sets of simulation time domain results.

Key words: low-voltage DC system, high-frequency oscillation, normalized reduced-order model, control parameters, feasible region