电容式电压互感器电压暂降测量误差分析及校正

电压暂降是影响现代电网最为突出的电能质量问题之一，在进行大范围高压系统电压暂降监测时，必须考虑到含储能元件的电容式电压互感器（capacitor voltage transformer，CVT）所造成的不利影响。根据CVT结构推导了其测量电压暂降的误差并指出了影响该误差的内外部因素，而后构建了仿真模型，详细研究了暂降初相角、残余电压、CVT参数及负荷对电压暂降持续时间、暂降幅值以及相位跳变等特征量的影响及敏感度，最后提出一种基于虚拟阻抗补偿的CVT电压暂降测量误差校正方法，消除了电压暂降不确定性造成的测量误差多样性问题，仿真结果表明该方法的有效性，为普遍采用CVT的高压系统电压暂降准确测量提供了可行的校正方案。

Application of Online Monitoring System of Mercury Emission in Flue Gas for Thermal Power Plant

The composition,monitoring principle and working process of the mercury flue gas automatic online monitoring system in Sanhe Power Plant were introduced.Inspected by the Hebei province environmental monitoring center,the data of continuous monitoring system were accurate and reliable.Data measured more than a year show that the total mercury emissions of flue gas concentration in Sanhe Power Plant were within 2.0～14.3 μg/m3,which belongs to the low level of mercury emissions and meets the mercury emissions limits requirements of the GB13223-2011 "The power plant standards for the discharge of atmospheric pollutants".The experiment proved that the application of wet flue gas desulfurization can effectively reduce the concentration of the Hg2+ in flue gas.