针对交直流混联系统的稳态特性,提出了一种增强控制策略以提高多端直流输电系统的稳定性.分布式补充控制结构通过调节换流器有功功率参考值来增强系统的角稳定性,基于对换流器公共连接点频率和角度的测量,确保在换流器达到功率限制时保持直流电网的功率平衡.在修改后的IEEE 39节点系统上进行的电磁暂态仿真验证了控制器的有效性.结果表明,使用补充控制策略的系统瞬态稳定性显著提高,临界故障清除时间从不足0.2 s提高到超过0.35 s.
Analysis of Enhanced Control Strategies for Multi-Terminal DC Transmission Systems on Steady State Characteristics of AC-DC Hybrid Systems
An enhanced control strategy is proposed to improve the stability of multi-terminal DC transmission systems,focusing on the steady-state characteristics of hybrid AC/DC systems.A distributed supplementary control structure is designed to enhance angular stability by adjusting the active power reference of converters.This control is based on measurements of frequency and angle at the converters'points of common coupling,ensuring power balance in the DC grid even when power limits are reached.Electromagnetic transient simulations on a modified IEEE 39-bus system validate the effectiveness of the proposed controller.Results show that the transient stability of the system is significantly improved,with critical fault clearing time increasing from less than 0.2 seconds to over 0.35 seconds.
AC-DC hybrid systemmulti-terminal DC transmissionenhanced control strategytransient stability
万方数据
维普
