The electrical locomotives are treated as single-phase nonlinear loads, which can cause the low power factor, high contents of harmonic currents, and negative-sequence current. The power quality conditioners are widely used for solving the power quality issues in the railway power system. In power quality conditioners, the coupled impedance can affect the operation voltage, compensation range, and performance. Therefore, this article discusses the effect of different coupled impedances in conditioners, including fixed inductive impedance, fixed capacitive impedance, and adaptive impedance. Moreover, an adaptive impedance-coupled hybrid power quality conditioner (AI-HPQC) is proposed in comparison with inductive-coupled railway power quality compensator (RPC) and capacitive-coupled hybrid power quality conditioner (HPQC). Furthermore, a control method for the AI-HPQC is proposed for the coordination control of the adaptive impedance part and the active inverter part. The validities of the RPC, HPQC, and the proposed AI-HPQC are verified by both simulation and experimental results.

中文翻译：

---

同相铁路牵引供电电能质量调节器自适应阻抗结构的设计与分析

电力机车作为单相非线性负载处理，会导致功率因数低、谐波电流含量高和负序电流。电能质量调节器广泛用于解决铁路电力系统中的电能质量问题。在电能质量调节器中，耦合阻抗会影响工作电压、补偿范围和性能。因此，本文讨论了调节器中不同耦合阻抗的影响，包括固定感性阻抗、固定容性阻抗和自适应阻抗。此外，与电感耦合铁路电能质量补偿器（RPC）和电容耦合混合电能质量调节器（HPQC）相比，提出了一种自适应阻抗耦合混合电能质量调节器（AI-HPQC）。此外，针对自适应阻抗部分和有源逆变器部分的协调控制，提出了一种AI-HPQC的控制方法。RPC、HPQC 和提出的 AI-HPQC 的有效性通过模拟和实验结果得到验证。