微机消谐原理
Microcomputer harmonic elimination principle
装置内的大功率消谐元件（可控硅）处于阻断状态，对系统无任何影响。当PT开口三角电压大于30V时，说明系统出现故障。装置开始对开口三角电压进行数据采集。通过数字测量、滤波、放大等数字信号处理技术，对数据进行分析、计算，判断出当前的故障状态。如果出现某种频率的铁磁谐振（一般在17Hz--150Hz之间），CPU立即启动消谐电路（使可控硅导通），让铁磁谐振在强大的阻尼下迅速消失。铁磁谐振消除后，CPU作相应纪录、存储，并自动报警、显示有关谐振信息(包括发生时间、频率、幅值等)如果是过电压或单相接地，CPU做出诊断后，装置分别给出显示和报警，并自动纪录、存储有关故障信息。最后，CPU返回初始状态，并继续检测开口三角电压
The high-power harmonic elimination element (thyristor) in the device is blocked and has no effect on the system. When the PT open delta voltage is greater than 30V, it indicates that the system is in trouble. The device starts to collect data on the open delta voltage. Through digital measurement, filtering, amplification and other digital signal processing technology, the data are analyzed and calculated to determine the current fault state. If a certain frequency of ferroresonance occurs (usually between 17Hz and 150Hz), the CPU immediately starts the harmonic elimination circuit (to turn on the SCR), allowing the ferroresonance to disappear rapidly with strong damping. After the ferroresonance is eliminated, the CPU records and stores the corresponding data, and automatically alarms and displays the resonance information (including the occurrence time, frequency, amplitude, etc.) If the CPU is over-voltage or single-phase grounded, the device gives the display and alarm respectively, and automatically records and stores the relevant fault information. Finally, CPU returns to the initial state and continues to detect the open delta voltage.