就地化保护测控装置滤波电路分析及测试

Filter circuit analysis and test of localized protection measurement and control device

采样的正确性是就地化保护测控装置的关键技术,需依据保护测控装置要求,设计截止频率合理的低通滤波电路,解决频率混叠的问题。因基波及谐波经过滤波电路后其幅值及相位会被影响,相应的补偿参数需正确。理论分析了滤波电路的截止频率、幅频特性及相频特性,并依据分析结果设计了保护程序。通过就地化保护测控装置校验仪测试采样值输出的幅值及相位精度,满足就地化保护测控装置的技术要求。

Correct sampling is the key technology to localized protection measurement and control device. According to the requirements of the protection and control device,a low-pass filter circuit with reasonable cut-off frequency should be designed to solve the problem of frequency aliasing. Since passing through the filter circuit will affect the amplitude and phase of the fundamental wave and harmonics,the corresponding compensation parameters need to be correct. It theoretical analysis the filter circuit cut-off frequency,amplitude and frequency characteristics as well as phase frequency characteristics,and protection program based on analytic results is designed. According to the amplitude and phase accuracy of the sampling value output of localization protection measurement and control device,the technical requirements of the localized protection measurement and control device are met.