Power supply system for graded power-up

Abstract

The invention discloses a power supply system for graded power-up. The power supply system mainly comprises a normally-closed alternating current contactor, a normally-open alternating current contactor, an AC / DC auxiliary circuit, an AC / DC main circuit and an isolation diode. After normal power supply, the normally-closed alternating current contactor controls the AC / DC auxiliary circuit to be started preferentially, and environment control equipment and the like are powered up in advance. After reasonable time delay, the normally-open alternating current contactor controls the AC / DC main circuit to be started to supply power to main electric equipment. After the output of the AC / DC main circuit is stable, the AC / DC auxiliary circuit is controlled to be closed, and only the main circuit works. The AC / DC auxiliary circuit only works in the power-on initial stage, so that the problem of extra power consumption caused by continuous work of the auxiliary circuit is completely solved, andmeanwhile, the reliability of the power supply is also greatly improved. Besides, only the AC / DC main circuit is left to work after the power supply is started, so that current harmonics can be effectively reduced only by adding the PFC circuit into the main circuit, the power factor of the whole power supply is improved, and the cost is saved while the power supply performance is improved.

Description

technical field [0001] The invention belongs to the technical field of power electronics, in particular to a power supply system for hierarchical power-on. Background technique [0002] At present, in order to monitor and control the system environment, large-scale industrial, living, and medical power systems usually add some environmental control equipment. Environmental control equipment needs to realize the status monitoring, control and protection, and fault alarm functions of the system environment before the main electrical equipment is powered on. Therefore, the environmental control equipment needs to be powered on first, that is, the power system is required to have the function of hierarchical power-on. In order to achieve hierarchical power-on, the power system generally follows the figure 1 The principle shown is designed. From figure 1 It can be seen that the power supply system is divided into two parts, one part is the main circuit, which is used to supply...

AI Technical Summary

Problems solved by technology

for figure 1 In the power system shown, if only the PFC circuit is added to the main circuit, the power factor correction effect will be greatly reduced due to the existence of the auxiliary circuit, and if the PFC circuit is added to the main circuit and the auxiliary circuit at the same time (such as figure 2 shown), which will greatly increase the cost of the circuit

For the second shortcoming, it is usually to add an auxiliary power supply as a backup (such as figure 2 As shown), when one of them fails, the other power supply is automatically connected to work to ensure the normal operation of the auxiliary circuit. However, the problem of additional power consumption still cannot be solved, and the circuit cost also increases accordingly

[0005] (1) The power supply system with hierarchical power supply has low power factor (PF), high current harmonic THDi, and cannot meet the requirements of equipment electromagnetic compatibility CE101 conducted emission test, etc.

If you want to improve harmonics and reduce electromagnetic interference, you need to add a PFC circuit to the main circuit and auxiliary circuit at the same time, and the circuit cost will increase greatly.

[0006] (2) The auxiliary circuit needs to work all the time after the power is turned on, which not only increases the power consumption, but also causes the entire power system to fail to operate normally if it is damaged

If the backup circuit is added, the reliability of the auxiliary circuit can only be slightly improved, and the problem of increasing power consumption cannot be solved, and the cost is also increased

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