基于无锁相环的电气化铁道功率平衡装置电流检测方法的研究

针对平衡变压器供电方式下，高速电气化铁道谐波、负序电流引起的电压畸变，指令电流检测过程复杂、延时较长，结果含有误差的缺点，提出了一种无需锁相环电路快速准确地提取指令电流的方法。该方法通过简单的数乘运算提取基波电压，运用同步检测法来准确地检测出指令电流信号的方法，使两供电臂功率平衡，电流对称且与供电臂基波电压同相位，消除无功、谐波及负序电流对三相电力系统的影响。相比传统的带锁相环，基于鉴相原理和瞬时无功功率理论的检测方法，该方法更加简便易行，运算速度更快，且不受电网畸变条件的影响。通过仿真分析，验证了该检测方法在电气化牵引供电系统电压畸变条件下运用的正确性和可行性。

Current detection method based on no phase-locked loop for electrified railway power balance device

Aiming at the shortcoming of voltage distortion caused by high-speed electrified railway harmonic and negative sequence current and the complexity and longer delay of command current detection process leading to results containing error under balance transformer power supply, this paper proposes a fast and accurate method to extract the instruction current without phase-locked loop circuit. The method extracts fundamental voltage by a simple number multiplication, and uses synchronous detection method to accurately detect the command current signal and to balance the power of two supply arms, make current symmetrical and phased with fundamental voltage of the supply arm, eliminating the effects of reactive power, harmonic and negative-sequence current on three-phase power system. Compared with traditional detection method with phase-locked loop based on principle of phase and instantaneous reactive power theory, this method is simpler and faster, and not subject to the effect of grid distortion. Simulation analysis verifies the correctness and feasibility of the detection method in the electrified traction power supply system voltage distortion.