With the rapid development of renewable energy, large amounts of power need to be transmitted to load centers, and series-capacitor compensation (SCC) plays an important role in renewable power transmission. However, it has been pointed out that SCC interacts with inverters and threatens system stability. This paper investigates the influence of SCC on inverter control, and proposes strategies for enhancing system stability based on the instability mechanism. First, the impacts of SCC on inverter current control and synchronization control are analyzed. A current control model is established by a system transfer function, and a synchronization control model focusing on transient stability is established based on the traditional synchronous reference frame phase-locked loop (SRF-PLL). Bode and nonlinear analysis methods are utilized in the stability analysis of both current control and synchronization control. It is found that SCC has little effect on inverter current control. However, it seriously affects synchronization control. SCC reduces the stability range of synchronization control, and causes system instability when there is a large frequency disturbance. In order to improve system stability, two approaches have been proposed. These approaches are optimizing a PI controller, and designing a band-pass filter (BPF) inside the PLL. Finally, simulations and experiments are presented to verify the correctness of theories.

随着可再生能源的快速发展，需要向负荷中心输送大量电力，串联电容补偿（SCC）在可再生电力输送中发挥着重要作用。然而，有人指出，SCC 与逆变器相互作用并威胁系统稳定性。本文研究了 SCC 对逆变器控制的影响，并提出了基于不稳定机制的增强系统稳定性的策略。首先分析了SCC对逆变器电流控制和同步控制的影响。通过系统传递函数建立电流控制模型，在传统同步参考系锁相环（SRF-PLL）的基础上建立以暂态稳定为重点的同步控制模型。波特和非线性分析方法用于电流控制和同步控制的稳定性分析。发现SCC对逆变器电流控制影响不大。但严重影响同步控制。SCC 降低了同步控制的稳定范围，当有较大的频率扰动时会导致系统不稳定。为了提高系统稳定性，提出了两种方法。这些方法正在优化 PI 控制器，并在 PLL 内设计带通滤波器 (BPF)。最后通过仿真和实验验证了理论的正确性。SCC 降低了同步控制的稳定范围，当有较大的频率扰动时会导致系统不稳定。为了提高系统稳定性，提出了两种方法。这些方法正在优化 PI 控制器，并在 PLL 内设计带通滤波器 (BPF)。最后通过仿真和实验验证了理论的正确性。SCC 降低了同步控制的稳定范围，当有较大的频率扰动时会导致系统不稳定。为了提高系统稳定性，提出了两种方法。这些方法正在优化 PI 控制器，并在 PLL 内设计带通滤波器 (BPF)。最后通过仿真和实验验证了理论的正确性。