基于Hanning窗插值FFT的介损测量装置设计

Dielectric Loss Measurement Device Based on Hanning Window Interpolation FFT

介质损耗是反映高电压电气设备绝缘受潮、劣化变质或气体放电等绝缘状况的重要指标,其准确测量对于电力系统安全、经济运行有着重要意义。针对高电压电气设备介质损耗在线监测的技术要求,本文提出了ADS8364+TMS320F2812的介损测量装置构成方案,详细介绍了六路同步采样ADC的数据采集单元和以TMS320F2812为核心的数据处理单元电路设计。传统FFT方法进行介损测量容易产生频谱泄漏和栅栏效应,影响测量的精度,而加窗插值FFT修正算法可以明显提高测量结果的准确性,消除频谱泄漏和栅栏效应引起的误差。为此本装置采用基于Hanning窗插值FFT算法实现介损准确测量与分析。仿真结果表明,基于Hanning窗插值FFT算法的介损测量装置能有效克服谐波干扰、基波频率波动、采样点数变化及噪声干扰的影响,试验结果验证基于Hanning窗插值FFT算法的介损测量装置测试介损结果精确,且受频率波动的影响较小。

Dielectric loss is a key indicator, reflecting insulation damping, deterioration or gas discharge of high-voltage electrical equipment insulation. Its accurate measurement is very important for the power system security and economy. According to the technology requirement of high-voltage electrical equipment, this paper has designed a dielectric loss measuring device, with its hardware based on ADS8364 and TMS320F2812. The hardware system is detailed, such as the sampling module and the data-processing module. The Hanning Window FFT Interpolation Algorithm is more advantageous than the traditional FFT algorithm in the dielectric loss measurement, as it can significantly improve the measurement accuracy of results, eliminating effects of spectrum leakage and fence. Therefore, it is used to accurately measure and analysis dielectric loss. Simulation and experimental results show that the device is accurate and stable, which can overcome the interference of the harmonics, frequency fluctuations and the impact of noise.