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...
Effect of Poor Power Factor The major effect of poor power factor is higher value of line current. We know that power factor (pf) is an important parameter for calculation of power in an AC circuit. For a given power and voltage, the current flowing through the line is inversely proportional to the power factor. This means that a poor power factor i.e. low power factor will result in hig...
3 phase load current imbalance In three phase systems, current unbalance is defined as the maximum deviation of any phase current from average divided by average current. Current unbalance can occur due to reasons within the control of the end user or outside the control of end user. Some of the reasons for current unbalance (or imbalance) are: Source voltage from the electric utility is unbalance...
With the development of society and the increase of demand for electricity, Reactive power compensation technology has developed rapidly, including Static VAR Compensation and Dynamic Reactive Power compensation, and has gained rich operating experience. However, some problems have also been exposed in practice. Some reactive power compensation devices are inconvenient to move, and the equipment m...
What is EMC testing EMC test (Electro Magnetic Compatibility) refers to the comprehensive evaluation of electromagnetic interference (EMI) and anti-interference capability (EMS) of electronic products. It is one of the most important indicators of product quality. The measurement of electromagnetic compatibility consists of test sites and test instruments. The purpose of EMC test is ...