基于改进小波阈值的低压电网继电保护输入信号辨识系统设计  

Design of low voltage power grid relay protection input signal identification system based on improved wavelet threshold

作　　者：戎瑜 柯春根 马伟 魏敏 RONG Yu;KE Chungen;MA Wei;WEI Min(Ma’anshan Power Supply Company of State Grid Anhui Electric Power Co.,Ltd.,Ma’anshan 243000,China)

机构地区：[1]国网安徽省电力有限公司马鞍山供电公司,安徽马鞍山243000

出　　处：《电子设计工程》2022年第10期167-171,共5页Electronic Design Engineering

摘　　要：针对当前低压电网继电保护输入信号辨识系统受到噪声信号干扰,存在信号辨识结果可靠性和精度较低的问题,设计了基于改进小波阈值的低压电网继电保护输入信号辨识系统。根据系统硬件结构,利用A/D转换模块,将电信号转换为数字信号,使用L298N驱动模块驱动直流电机,用以保护过流,使供电与负载供电分离。设计RS485通信接口,将查询信息传送给从机,避免接收错误数据,采用TMS320LF2407 DSP芯片,通过JTAG口将数据传输至仿真器上,实现输入信号辨识。利用改进小波阈值识别算法,在保留初始信号完整的同时,剔除噪声信号,确定低频系数绝对总值和高频系数绝对总值,并设计辨识流程,实现低压电网继电保护输入信号辨识。实验结果表明,通过阶跃信号、正弦信号,验证了该系统的可靠性较高,且识别精度高达0.98,具有精准的识别效果。The input signal identification system of relay protection in low-voltage power grid is disturbed by noise signal,and the reliability and accuracy of signal identification results are low.A low-voltage power grid relay protection input signal identification system based on improved wavelet threshold is designed.According to the hardware structure of the system,the A/D conversion module is used to convert the electrical signal into digital signal,and the L298N drive module is used to drive the DC motor to protect the over-current and separate the power supply from the load.The RS485 communication interface is designed to transmit the query information to the slave to avoid receiving the wrong data.The TMS320LF2407 is adopted DSP chip transmits the data to the simulator through JTAG port to realize the input signal identification.By using the improved wavelet threshold recognition algorithm,the noise signal is eliminated while the initial signal is intact,and the absolute value of low frequency coefficient and high frequency coefficient are determined.The identification process is designed to realize the input signal identification of low-voltage power grid relay protection.The experimental results show that the system has good reliability through the verification of step signal and sine signal,and the recognition accuracy can be as high as 0.98.

关 键 词：改进小波阈值 低压电网继电保护 输入信号 辨识系统 

分 类 号：TM501[电气工程—电器]