Generation of outlet power noise

Update:06-12-2019
Summary:

The generation of socket power noise can generally be d […]

The generation of socket power noise can generally be divided into the following two categories
1. Interference caused by internal components of the socket power supply
Socket power is a power source that rectifies the power frequency AC to DC, then converts it to high frequency AC through a switching circuit, and then rectifies it into a stable DC. In this way, there are the following types of noise: the high-order generated by the rectified waveform distortion of the outlet Harmonic noise; When the switching device is turned on and off at high current and high voltage, its current and voltage change sharply, forming a wide-band electromagnetic interference noise; surge current peaks and high voltages generated during the turn-on and turn-off of the rectifier diode Frequency noise; in addition, the input end of the output filter generates electromagnetic interference noise caused by oscillation due to the transformer leakage inductance, the distributed capacitance and the filter inductance capacitance.
2. Interference due to external factors
The external electromagnetic field interference enters the socket power through radiation or enters the socket power through the power cord. This interference can be divided into the following two types.
(1) Artificial interference source. With the rapid development of modern science and technology, electronics, power electronics, and electrical equipment have begun to be widely used. The high-density, wide-spectrum electromagnetic signals generated during operation fill the entire space and form a complex electromagnetic environment. In particular, transient electromagnetic interference has a voltage amplitude of 髙 (a few hundred volts to thousands of volts), a fast rise speed, a short duration, and strong randomness. In addition, radar, navigation, communication and other equipment generate radio noise with a wide frequency range and high interference intensity.
(2) Natural interference sources. For example, the lightning discharge phenomenon and the sky electricity interference noise such as sunspots and cosmic rays in the universe, the former has a short duration but high energy, and the latter has a wide frequency range.