应用于复杂工况的输出电流自锁相SVG控制策略

静止无功发生器SVG（static var generator）的无功调节功能依赖其网相位跟随能力，因此受锁相环节影响较大。当电网存在背景谐波、不对称运行等复杂工况时，基于系统电压锁相的方式需要设计正/负序提取、谐波提取等辅助环节，增加了系统的复杂度与非线性。基于此，提出了一种基于输出电流自锁相的SVG控制策略，在不添加辅助环节的前提下提高了SVG在复杂工况下的适应能力。首先，对SVG的控制策略与锁相方式进行了阐述，分析了不同工况下SVG的输出特性。然后，详细解释了所提自锁相方法的工作机理，论证了电流自锁相具备较好的环境适应能力，并通过Bode图分析验证了所提策略具备良好的响应特性。最后，通过实验验证了理论分析的正确性。

SVG Control Strategy Based on Output Current Self-phase-locking under Complex Working Conditions

The reactive power regulation function of a static var generator(SVG) depends on its phase following capability, so it is greatly affected by phase-locking. When the grid is operating under complex working conditions such as background harmonic and asymmetric operation, the phase-locking method based on system voltage needs to design auxiliary links including positive/negative sequence extraction and harmonic extraction, which increases the complexity and nonlinearity of the system. On this basis, an SVG control strategy based on output current self-phase-locking is proposed in this paper, which improves the adaptability of SVG under complex working conditions without adding auxiliary links. First, the SVG control strategy and phase-locking method are elaborated upon, and the output characteristics of SVG are analyzed under different working conditions. Then, the operation mechanism of the proposed self-phase-locking method is explained in detail, and it is proved that the current self-phase-locking has a good adaptability to the environment. In addition, the response characteristics of the proposed strategy are verified through the Bode graph analysis. Finally, the theoretical analysis was verified by experimental results.