【摘要】 变频法可降低工频干扰对地网接地电阻测量的影响.现场测试发现,有些杆塔处因工频干扰过强导致接地电阻变频测试仪无法工作或测量误差很大.计算分析发现,在土壤电阻率较高和导线换位的杆塔处易出现强工频干扰电压.为有效抑制工频干扰对杆塔地网接地电阻测量的影响,开发出可调反相信号源,串入测量回路中,可使信号源信号与工频干扰信号同幅同频且反相从而达到抵消工频干扰的目的.实验室模拟试验和现场测试表明,该方法可有效抑制工频干扰,确保接地电阻变频测试仪在强干扰条件下正常工作.更多还原

【Abstract】 Using variable frequency grounding resistance tester can decrease the power frequency interference effects on tower grounding resistance measurement.Field test found that the power frequency interference is too large to lead tester cannot work normally in some tower area.Through calculating and analyzing,it is found that in the area of high soil resistivity like mountains and conductor transposition tower place are prone to large interference power frequency voltage.Putting a variable source string into the measuring circuit,make the source of signal and power frequency interference signal with amplitude and frequency and the phase offset interference of power frequency test method to offset the power frequency interference.Through simulated test and field test,proving serial-in the string into the adjustable signal source can reduce the interference voltage tester and make variable frequency grounding resistance tester working properly.更多还原