基于差分傅里叶算法和滤波技术的过电压保护装置检测法  

Detection method of overvoltage protection device based on differential Fourier algorithm and filtering method

作　　者：李勇 胡建华 柳鹏 彭发荣 LI Yong;HU Jianhua;LIU Peng;PENG Farong(China Energy Science&Technology Research Institute Co.,Ltd.,Yinchuan Branch,Yinchuan Ningxia 750011,China)

机构地区：[1]国家能源集团科学技术研究院有限公司银川分公司,宁夏银川750011

出　　处：《宁夏电力》2023年第5期66-70,共5页Ningxia Electric Power

摘　　要：为解决火电厂发电机过电压侵害威胁发电机定子及变压器安全的问题,提出一种基于差分傅里叶算法和滤波技术的发电机转子过电压保护装置检测方法。首先,在现场采集发电机过电压保护测试仪的电压结构参数。其次,应用脉冲宽度调制(pulse width modulation,PWM)技术和大功率绝缘栅双极晶体管(insulated gate bipolar transistor,IGBT)器件及其驱动技术,解决了传统过电压保护测试仪输出电压和直流输出不够稳定的问题。在此基础上,引入差分傅里叶算法和滤波技术,实现信号的完全输出以及控制的分析、处理、保护等功能,解决了传统过电压保护测试仪信号输出不全以及无法滤波的问题。最后,选取不同电厂机组励磁系统进行过电压保护试验。试验结果表明,所提方法能有效地完成转子过电压保护校验工作,其电压输出值远小于转子绕组出厂工频试验电压幅值的70%,机组励磁系统转子过电压保护逻辑动作正确,动作电压值符合要求,验证了所设计测试方法的有效性和准确性。In view of the phenomenon that the generator overvoltage in thermal power plants threatens the safety of generator stator and transformer,a test method of intelligent generator rotor overvoltage protection device based on diffe-rential Fourier algorithm and filtering technology is designed.First of all,the voltage structure parameters of the generator overvoltage protection tester are determined by investigating the test principle of rotor overvoltage protection devices of different generator sets on site.Secondly,high frequency voltage doubling circuit,PWM high frequency pulse width modulation technology and high-power IGBT device and its driving technology are used to improve the stability of voltage and DC output respectively.Finally,through the differential Fourier algorithm and filtering technology,complete the signal output,realize the control analysis,processing,protection and other functions,and select different power plant excitation systems for overvoltage protection tests.The results show that the verification of rotor over-voltage protection can be effectively completed by testing different excitation systems in China,which is far less than 70%of the voltage amplitude of rotor winding factory power frequency test.The logic action of rotor over-voltage protection of unit excitation system is correct,and the action voltage value meets the requirements,which verifies the effectiveness and accuracy of the designed test method.

关 键 词：发电机转子 过电压保护 PWM 差分傅里叶算法 滤波技术 

分 类 号：TM862[电气工程—高电压与绝缘技术]