English

中文版

English

NEWS

/

/

/

How to solve harmonic filter

Categories:Industry News
Author:
Origin:
Time of issue:2022-05-20
Views:

(Summary description)Harmonic filter is an important issue in the field of power quality. The harmonics of power grid come from three aspects.





How to solve harmonic filter

(Summary description)Harmonic filter is an important issue in the field of power quality. The harmonics of power grid come from three aspects.

Categories:Industry News
Author:
Origin:
Time of issue:2022-05-20 16:24
Views:

Information

Harmonic filter is an important issue in the field of power quality. The harmonics of power grid come from three aspects:

Firstly, the quality of power generation source is not high, resulting in harmonics;

Secondly, the transmission and distribution system generates harmonics;

Thirdly, harmonics are generated by electrical equipment. Among them, electric equipment produces more harmonics.

What should we do?

i. Harmonic detection shall be carried out regularly. The competent department of distribution network shall regularly organize professional technicians to systematically analyze the power grid under its jurisdiction, and make correct measurement and scientific records and statistics to determine the specific location and causes of harmonic sources. Long term observation points can be set in places with large fluctuation of harmonic generation in distribution network to collect reliable data.
ii. Apply passive harmonic filter device. At present, passive filter device is one of the effective harmonic control measures in distribution network. Passive filter device has the advantages of low cost, mature technology and reactive power compensation. It uses the resonant characteristics of inductance, capacitance and other components to form a low impedance branch in the impedance shunt circuit, so as to reduce the harmonic current flowing to the power grid. However, in practical application, we should pay attention to controlling the load parameters of filter compensation to prevent the change of filter characteristics.
iii. Transform the capacitor. As the frequency of distribution network increases, the capacitive reactance will decrease. The capacitor is particularly sensitive to the harmonic component of the supply voltage, that is, a relatively small proportion of the harmonic voltage can cause a large current to flow into the capacitor circuit. If the natural frequency of the reactance connected to the capacitor banks or power system is close to a specific harmonic, local resonance will occur. Therefore, when the current increases in the distribution network, the following methods can be adopted: active power filter, hybrid filter, parallel harmonic filter or harmonic control reactor.
iv. Reduce the current waveform. In the comprehensive treatment of harmonic in distribution network, although the filter circuit can effectively control the current interference, there are still some technical loopholes to solve the distortion of current waveform. In the harmonic control of distribution network, effective measures are taken to reduce the current waveform without distortion, so as to achieve the effect of scientifically reducing the current harmonic content.