基于双频信号注入法的船舶交流电网绝缘监测装置应用探析

Application analysis of insulation monitoring device in marine AC power grid based on dual frequency signal injection method

为了解决船舶交流电网绝缘故障实时在线监测定位问题,提出了一种基于双频信号注入法的船舶交流电网绝缘监测装置设计方案。对双频信号注入法的工作原理进行研究,系统以STM32F103ZE芯片为控制核心,运用基2时间抽取1024点FFT实现注入低频信号的提取。明确了注入信号的频率选取原则,试验分析确定注入信号频率为15 Hz和5 Hz。经过实际运行测试与结果分析,基于双频信号注入法的船舶交流电网绝缘监测装置最大误差率不超过2%,完全满足对地绝缘电阻测量精度±5%的设计要求。试验结果验证了船舶交流电网绝缘监测装置的可靠性和有效性,所提出设计方案大大降低船员工作强度,提高了舰船电力系统的供电连续性和安全性。

In order to solve the problem of real-time online monitoring and location of insulation faults in marine AC power grid,this paper proposes a design scheme of marine AC network insulation monitoring device based on dual-frequency signal injection method.The system uses STM32F103ZE chip as the control core and 1024 points FFT to extract injected low frequency signals.The principle of frequency selection of injected signal is clarified,and the frequency of injected signal is determined by test analysis.After the actual operation test and result analysis,the maximum error rate of the insulation monitoring device based on the dual frequency signal injection method is less than 2%,which fully meets the design requirement which is±5%of the insulation resistance measurement accuracy.The test results verify the reliability and effectiveness of the insulation monitoring device of the marine AC network.The proposed design scheme greatly reduces the work intensity of the crew and improves the continuity and safety of the marine AC network.