The Active Harmonic Filter AHF unit is an electronic measuring instrument used in natural science-related engineering and technical fields. During the spurious emission process of communication equipment, the wireless communication signals in the GSM, GSMR and CDMA frequency bands are filtered, which generally consists of capacitors, resistors and inductors. During the operation of the AHF Harmoni...
The inductor is a component that can convert electrical energy into magnetic energy and store it. The structure of the inductor is similar to that of a transformer, but there is only one winding, which only hinders the change of current. If the inductor is in the state of no current passing through, when the circuit is connected It will try to hinder the flow of current through it. If the inductor...
Meaning Of Harmonics Harmonic refers to the electric quantity whose frequency is an integral multiple of the fundamental wave contained in the current. Generally, it refers to the Fourier series decomposition of the periodic non sinusoidal electric quantity. Except for the electric quantity of the fundamental wave frequency, the electric quantity generated by the current greater than the fundament...
Effects of Harmonics : Increased losses Losses in capacitors The harmonic voltages applied to capacitors cause the flow of currents proportional to the frequency of the harmonics. These currents cause additional losses. Losses in conductors The active power transmitted to a load is a function of the fundamental component I1 of the current. When the current drawn by the load contains harmonics...
Why is the harmonic current on the null line mainly three times? This is due to two reasons: (1) Among the harmonic components generated by single-phase rectifier circuit, the third harmonic is the largest, and the distortion rate of the third harmonic usually reaches more than 80%. (2) The harmonic current of other times will have the effect of canceling on the zero line, onl...
What is power quality? The IEC (1000-2-2/4) standard defines power quality as follows: power quality refers to the physical characteristics of power supply devices that do not interrupt or interfere with users' use of power under normal working conditions. The most serious power quality problems are voltage sags and complete voltage interruptions. In fact, power quality refers to the...
Due to the rapid development of power electronic technology, the nonlinear characteristics of industrial and agricultural power loads, especially transportation and civil electrical products are becoming more and more serious, and the power factor of users is also declining. Therefore, reactive power compensation devices are more and more widely used. The power compensation device is used to suppl...
Three-phase lines are common: three-phase three wire, three-phase four wire The three - phase three - wire system is star connection neutral point ungrounded and Angle connection method, the general high - voltage power supply uses three - phase three - wire system, three - phase four - wire is star connection neutral point grounding, low - voltage system uses three - phase four - wire system. &nb...