The microcomputer harmonic elimination device can display the system clock in real time, and display the total voltage and main vibration frequency of Pt opening of 1-4 sections of bus through key operation. It can distinguish overvoltage and resonance. It has been proved by the field operation of large enterprises such as electric power, metallurgy, coal, petroleum and chemical industry that the performance of the refitting device is superior and the use is safe and reliable.

The micro-computer harmonic elimination resonance parameter is the threshold value of zero sequence voltage to start the elimination coordination under the condition of frequency division, fundamental frequency and frequency multiplication. If the zero sequence voltage is greater than or equal to the threshold voltage, the microcomputer harmonic elimination device analyzes the open triangular voltage data of voltage transformer, judges which frequency of ferromagnetic resonance is the current fault state, quickly starts the harmonic elimination circuit to eliminate, and records the fault information Send out harmonic elimination alarm signal.

The intelligent microcomputer harmonic elimination device monitors the voltage and frequency at the opening triangle of the voltage transformer in real time. When ferromagnetic resonance occurs, the resonance element will be started instantly to produce strong damping and eliminate resonance. Most of the micro-computer harmonic elimination devices use single-chip microcomputer as the core component, and collect zero sequence voltage through the open triangle voltage of the electric voltage transformer for cyclic detection. Under normal working conditions, the voltage is less than 30V, and the high-power harmonic elimination element in the device is in blocking state, which has no effect on the system. When the open delta voltage of the voltage transformer is greater than 30V, it indicates that the system is in fault. The device starts to collect the data of the open delta voltage. Through digital signal processing technologies such as digital measurement, filtering and amplification, the data are analyzed, calculated and judged to determine the current fault state. If there is a certain frequency of ferromagnetic resonance, the harmonic elimination circuit will be started immediately to make ferromagnetic resonance It disappears quickly under strong damping. The microcomputer harmonic elimination device perfectly solves the problem of harmonic elimination in the power system, and can record the number and frequency of resonance.