电气化铁路中谐波、无功、负序电流的实时检测方法

为了检测电气化铁路供电系统中的谐波、无功和负序电流，提出了两种基于FBD法的实时检测方法：直接法与间接法。直接法的特点是：根据电网电压的波形分析电流，使功率电流的波形与系统电压的波形完全相同，检测结果易受电压波形的影响，适用于电压波形稳定、无畸变的场合。间接法利用锁相环生成参考电压波形，功率电流的波形与参考电压波形完全相同，检测结果不受实际电压波形畸变的影响。直接法与间接法中没有Park变换，比基于瞬时无功功率理论的检测方法简单，而且适用于从单相到多相电路。仿真结果和实验结果验证了检测方法的正确性。

DETECTING METHODS OF REACTIVE POWER, HARMONIC AND NEGATIVE-SEQUENCE CURRENT IN ELECTRIFIED RAILWAY SYSTEMS

In order to detect the harmonic currents, reactive power and negative-sequence currents in traction power system, two detecting methods based on FBD-method, direct- and indirect-method, are proposed in this paper. In direct-method, current is analyzed based on voltage waveform. The waveform of power current is same to the voltage waveform, so the detecting results are influenced by the voltage. Direct-method is suit to the situation that the voltage is stable and has no distortion. In indirection-method, a reference voltage is generated by PLL, the waveform of power current is same to the reference voltage waveform, so detecting results aren't affected by the voltage waveform. There is no Park transformation in direct-method and indirect-method, so the algorithm is simpler than the instantaneous reactive power theory, and they suit to single- even poly-phase circuit. Simulation results and experimental results based on prototype active power quality compensator proved the detecting methods.