摘要
三相V/v变压器在高速铁路中广泛使用。高速电力机车作为单相PWM负载,在电网产生严重的负序、3次谐波和频带较宽的高次谐波电流。该文提出由三相三绕组V/v变压器、无源滤波器和三相电压源逆变器(voltage source inverter,VSC)组成的综合补偿系统。三相V/v变压器带补偿绕组,补偿绕组采用零等值阻抗设计,直接匹配为VSC电压等级,省去两台降压变压器;无源滤波器采用感应滤波技术设计,包括3次单调谐滤波器和高通滤波器;VSC仅补偿负序电流,降低了开关频率。详细阐述了系统方案,利用等效电路分析基于感应滤波技术的谐波抑制原理,得出滤波器设计方法,推导负序电流补偿原理,并提出一种新的参考电流检测算法。该算法避免了检测网侧相电压而三相V/v变压器无网侧中性点的矛盾,采用准比例谐振VSC控制方法,在电网频率波动时仍有良好的电流跟踪效果。仿真与实验结果验证了所提方案和控制方法的正确性。
The three-phase V/v transformer is widely used in high-speed railway. The high-speed electric locomotive as a single phase PWM load produces serious negative sequence, third harmonic and a wide-band high order harmonic currents. A novel compensation system was proposed in the paper, which consists of a three-phase three windings V/v transformer, passive filters and a three-phase voltage source inverter （VSC）. The V/v transformer has a compensation winding, which was designed to be zero equivalent impedance and was connected directly with VSC, so two step-down transformers are saved. The passive filters consist of a single tuned filter for third harmonic and a high pass filter using inductive filtering technology design. VSC only compensate the negative sequence current, which can reduce the switching frequency. The operation principle of the system was elaborated. The harmonic suppression theory with inductive filtering technology was analyzed using the equivalent circuit and the design methods for passive filters were introduced. The negative sequence current compensation principle was deduced, and a novel reference current detection algorithm was obtained, which avoids detecting primary phase voltages while there is not a neutral point in the V/v transformer. The quasi proportional resonance was presented which has good current tracking effects even when fluctuation of the grid frequency. Simulation and experimental results show the correctness of the proposed system and the control method.
出处
《中国电机工程学报》
EI
CSCD
北大核心
2013年第30期128-135,19,共8页
Proceedings of the CSEE
基金
国家自然科学基金项目(51077044
51077045)
湖南省科技计划项目(2012FJ4372)
湖南省教育厅一般项目(10C0549)~~
