一种低耐压中性线谐波治理电路原理及实现

介绍了一种新型低耐压中性线谐波治理装置的主电路结构，并对其工作原理进行了分析。该结构基于零序谐波电压互感器思路。采用单相桥式逆变电路，其输出通过变比为1：1的隔离变压器与系统相连，不会增加逆变器承受的电流。隔离变压器原边采用Y0接法，副边采用开口三角形接法，逆变器无需承受系统基波电压，只承受零序谐波电压和不平衡电压，降低了主电路承受的电压；采用的器件少且电压等级低，节约了成本；直流侧电容由三相二极管整流器充电。并且由于补偿零序谐波，直流侧与交流侧交换的有功功率很小，因此无需对直流侧电压进行控制。研制了一套试验装置，通过实验结果分析可以看出，该电路具有耐压低、结构和控制简单、运行可靠等优点。

CONFIGURATION AND REALIZATION OF A NEUTRAL HARMONIC CURRENT CONDITIONER

The main circuit of a novel neutral harmonics current conditioner and its control principle are described. The main idea is based on the sensor of zero-phase sequence harmonics voltage. In the main circuit, the single-phase inverter connects with the power system by a Y0, d transformer. Hence, the inverter does not provide the base wave voltage, and only needs to supply zero-phase sequence harmonics voltage and imbalance voltage. Fewer power electronics components are required to construct the main circuit. These all reduce the ratings and cost of the conditioner. Because of a three-phase diode rectifier in DC side and the zero-sequence harmonics current being compensated, the level of active power flow between DC side and AC side is very low, and the voltage on the DC side needs not to be controlled. The experimental results show that the proposed main circuit is of many advantages, such as low endurable voltage, simple topology and control, and higher running reliability, etc.