What does harmonic current mean Harmonic current is a collective term for the sinusoidal components whose frequency is an integer multiple of the original periodic current frequency. A harmonic current with a frequency equal to k times the frequency of the original periodic current is called a k-th harmonic current, and all harmonic currents with a frequency greater than 1 are collectively referre...

The fundamental cause of harmonic generation is due to nonlinear loads. When the current flows through the load and does not have a linear relationship with the applied voltage, it forms a non sinusoidal current, resulting in harmonics. The suppression of harmonics in the power system is to reduce or eliminate the harmonic current injected into the system, in order to control the harmonic voltage ...

1. Definition of harmonics In the AC power grid, due to the operation of many nonlinear electrical equipment, the voltage and current waveforms are actually not complete sine waveforms, but non-sine waves with different degrees of distortion. Harmonic refers to the amount of electricity contained in the current whose frequency is an integer multiple of the fundamental wave, and generally refers to...

1. Nonlinear characteristics   The diodes, thyristors and other power electronic devices in rectifier equipment have nonlinear voltammetry characteristics. Take the diode as an example, when the input AC voltage is in positive half circle, the diode is positive and the current can pass through; At the negative half cycle, the diode is reversed off and the current is almost zero. This characte...

With the increasing use of nonlinear loads such as variable frequency drives, rectifiers, and other power electronic devices, power grid harmonics have become a common problem in low-voltage electrical systems. Low-voltage active power filters (APFs) play a key role in detecting and mitigating harmonic distortion to improve power quality. Here’s how APFs work to actively compensate for harmonics i...

As modern power systems rely more on nonlinear loads, Total Harmonic Distortion in Current (THDi) has become a critical factor in ensuring power quality and equipment longevity. In this article, we explore what THDi is, its causes, its impacts on equipment, and how to mitigate it using advanced harmonic filtering techniques. 1. What is THDi? THDi stands for Total Harmonic Current Distortion. It is...