基于LabVIEW的考虑CVT宽频传输特性的谐波分析系统设计

Design and Development of Harmonics Monitoring System Considering Wide-band Transfer Characteristics of CVT Based on LabVIEW

随着电网的发展,直流工程和新能源项目的建设,开关电源、晶闸管器件、风电机组等在电网中越来越多的得到应用。但同时产生的谐波电流还会引起电网中线电流的超载,影响电网对电力的传输能力。因此对系统谐波的监测是电力系统必不可少的测试环节。目前在进行电压谐波测试时采用的方法都是将谐波分析仪直接连接到电容式电压互感器(CapacitorVoltage Transformer,简称CVT)二次侧进行测试,没有考虑电网谐波各频段经过CVT的变比不同导致对反演电网谐波存在一定失真。提出了一种基于LabVIEW的考虑CVT宽频传输特性的谐波分析仪,经过仿真测试,能准确的反演真实的电网谐波,具有很好的实用价值。为根据测量分析所得数据进行电网谐波治理提供了更准确的依据,从而更好的提高电网的稳定性。

With the development of the power network, DC engineering and new energy project construction, more and more facilities such as switching power supplies, thyristor devices, wind generators have been applied in the power system. But the produce of the harmonic current can also cause overload of the neutral current in the power system at the same time, affect the transmission capacity of the power system. So the test to the system harmonic monitoring is an indispensable part of the power system. At present, the method of voltage harmonic test is connecting directly to the Capacitor Voltage Transformer（ referred to CVT） in the secondary side with the harmonic analyzer. Without considering the ratio of each frequency band of the harmonic wave in the power of the change is different after passing the CVT, so there are certain distortion when inverting the real harmonic wave in the power system. A design and development of harmonies monitoring system considering wide-band transfer characteristics of CVT based on LabVIEW is proposed, it can invert the real harmonic exactly through the testing, so it has very good practical value. According to the analysis of the measuring data provides a more accurate basis for the harmonic management in the power system, so it is better to improve the stability of the power system.