Abstract:
This paper introduces the application of the AC input protection scheme of the high frequency switching power system with ABB High and low voltage monitoring module (CM-PVE) as the core component in the actual project, and can also be used as reference for other equipment when the input protection scheme is used in the unstable areas where the mains power is not very standard.
Background:
Communication high frequency switching power supply with mobile base stations constantly from the grid conditions of better towns to remote areas coverage. Although the high frequency switching power supply has a wide range of voltage, the damage rate of the AC input part of the rectifier is increasing increasingly. The damage accounts for the vast majority of passive devices such as input fuse and input rectifier bridge. The grid conditions in these areas are very complex, either because of small hydropower or because of many minefields. Other empirical data show that rectifier design has become mature and sophisticated (especially for imported brands such as EATON, the thermal design is quite scientific, and the reliability and consistency of operation under normal grid conditions are also quite good). The rectifier failure rate is statistically very low in areas with good grid conditions (excluding the condition of normal waveform with only amplitude variation). These have little impact on the equipment), but the rectifier damage rate in remote areas is high, and the cost is particularly high because the base station is unattended and inconvenient to maintain. This contradiction is emerging day by day, how to solve?

IC693PWR322F

IC693PWR322F

IC693PWR322F

Although the surge suppressor has irreplaceable advantages such as fast response speed and constant electricity when the voltage limiting operation, it is only suitable for absorbing transient high voltage energy such as 8/20 s, 10/1000 S-level waveform, power grid overvoltage such as closing, large capacity capacitive and inductive load, three-phase unbalance, phase line to ground short circuit fault and other overvoltage will cause the number of surge protector damage greatly increased, and if the high rated voltage of the surge protector will make the protection level of the surge protector increased (i.e. residual voltage increased), so that the protected equipment damage probability greatly increased. Thus, the scheme of over-voltage and under-voltage protection device comes into being.
The basic principle of the scheme:
The overvoltage protection device can be composed of four parts: the front stage of high rated (high residual pressure) surge protection, detection mold fast, action mechanism, the rear stage of low rated (low residual pressure) surge protection. This apparently resolves the contradiction above, which I won’t go into detail here. The design of the action mechanism is exquisite. In brief, it is necessary to consider the wide range and automatic recovery. And here we focus on the selection and application of detection mold fast. In this scheme, the fast detection mode can be said to be the core. Improper selection not only has a higher failure rate, but also cannot achieve the expected protection effect of the scheme.